Chair Organizing Committeephysics.skku.ac.kr/symposium/60anniv/Excerpt.pdf · Charge dynamics of...

ChairSungkyunkwan University

Chong-Yun Park

Joo Yull Rhee

Organizing CommitteeSungkyunkwan University

Joung Real Ahn

Seung-Woo Hong

Jungseek Hwang

Won Nam Kang

Dae Joon Kand

Il Hung Park

Seong Chan Park

Sung Ha Park

Tuson Park

Carsten Rott

Scientific SecretarySungkyunkwan University

Kyung Yuk Chae

Woo Seok Choi

TIME TABLETime Nov. 05 (Wed.) Nov. 06 (Thu.) Nov. 07 (Fri.)

08:30 - 09:00 Registration & Refreshment

09:00 - 09:30 Misao Sasaki (W1) Harold Y.Hwang (T1) Sang-Wook Cheong (F1)

09:30 - 10:00

10:00 - 10:30 Doug Cowen (W2) Young Hee Lee (T2) Hideo Hosono (F2)

10:30 - 11:00

11:00- 11:30 Coffee Break

11:30 - 12:00 Paolo Gondolo (W3) Hiroshi Eisaki (T3) Wooyoung Lee (F3)

12:00 - 12:30 Yeongduk Kim (W4) Tuson Park (T4) Hsiang-Lin Liu (F4)

12:30 - 13:00 Lunch

Lunch Lunch 13:00 - 13:30

13:30 - 14:00 Eun Suk Seo (W5)

14:00 - 14:30 Takashi Teranishi (W6)

Excursion

Chul-Hong Park (F5)

14:30 - 15:00 Young Kwan Kwon (W7)

Christos Panagopoulos (F6)

15:00 - 15:30 Nobuchika Okada (W8) Tsuyoshi Tamegai (F7)

15:30 - 16:00 Break Break

16:00 - 16:30 Yuta Hamada (W9) Dong Ho Wu (F8)

16:30 - 17:00 Jinn-Ouk Gong (W10) Jung-Woo Yoo (F9)

17:00 - 17:30 Ki-Young Choi (W11) Jiwoo Nam (F10)

17:30 - 18:30 Poster SessionBanquet Dinner

18:30 - 19:30

VENUESamsung Library, Sungkyunkwan University

7F Acquisition Department, Creative Learning Room

6F IT Center

5F Cafe (Coffee break), Poster presentations

4F Reading Rooms

3F Collections, Group study rooms

2F Group study rooms, Reading rooms

1F Information desk, Reading rooms

B1F Auditorium (Invited talks)

INVITED TALKSNo. Time Name / Affiliation Title

Nov. 5 (Wed.) Morning Session ⅠChair: Seong Chan Park

W1 09:00 - 10:00Misao Sasaki

Yukawa Institute, Japan Reviving Open Inflation

W2 10:00 - 11:00Doug Cowen

Pennsylvania State University, USA

Neutrino Physics with IceCube and Its Extensions

Nov. 5 (Wed.) Morning Session ⅡChair: Carsten Rott

W3 11:30 - 12:00 Paolo GondoloUniversity of Utah, USA Dark Matter

W4 12:00 - 12:30Yeongduk KimCUP/IBS, Korea

Searches for Dark Matter and Neutrinoless Double Beta Decay

at CUPNov. 5 (Wed.) Afternoon Session Ⅰ

Chair: Il Hung Park

W5 13:30 - 14:00 Eun Suk SeoMaryland University, USA

Current Results and Prospects of Cosmic Ray Experiments

W6 14:00 - 14:30 Takashi TeranishiKyushu University, Japan

Spectroscopy of unbound states in unstable nuclei using

spin-polarized proton resonance scatteing

W7 14:30 - 15:00Young Kwan Kwon

RISP/IBS, KoreaFacility for low energy nuclear

physics at RAON

W8 15:00 - 15:30Nobuchika Okada

University of A labama, USA

Implications of Higgs boson discovery to physics beyond the

Standard ModelNov. 5 (Wed.) Afternoon Session Ⅱ

Chair: Kyung Yuk Chae

W9 16:00 - 16:30 Yuta HamadaKyoto University, Japan

Higgs inflation from Standard Model criticality

W10 16:30 - 17:00 Jinn-Ouk GongAPCTP, Korea Running of the primordial spectra

W11 17:00 - 17:30 Ki-Young ChoiKASI, Korea

Sneutrino dark matter and its phenomenology

No. Name Name / Affiliation TitleNov. 6 (Thu.) Morning Session Ⅰ

Chair: Sung Ha Park

T1 09:00 - 10:00 Harold Y. HwangStanford University, USA

Emergent Phenomena at Oxide Interfaces

T2 10:00 - 11:00Young Hee Lee

Sungkyunkwan University, Korea

Recent progress on graphene growth

Nov. 5 (Thu.) Morning Session ⅡChair: Woo Seok Choi

T3 11:30 - 12:00

Hiroshi EisakiNational Institute of Advanced Industrial

Science and Technology, Japan

Charge dynamics of doped BaFe2As2 : Role of chemical

substitution and necessary ingredients for high-Tc

superconductivity

T4 12:00 - 12:30Tuson Park

Sungkyunkwan University, Korea

Superconductivity and Quantum Criticality

No. Name Name / Affiliation TitleNov. 7 (Fri.) Morning Session Ⅰ

Chair: Dae Joon Kang

F1 09:00 - 10:00Sang-Wook Cheong

Rutgers University, USADomain Topology and Color

Theorems

F2 10:00 - 11:00Hideo Hosono

Tokyo Institute of Technology, Japan

Iron Based Superconductors: Discovery and Current Status

Nov. 7 (Fri.) Morning Session ⅡChair: Joung Real Ahn

F3 11:30 - 12:00Wooyoung Lee

Yonsei University, KoreaAllotropic-like bismuth nanowires

at ambient condition

F4 12:00 - 12:30Hsiang-Lin Liu

National Taiwan Normal University, Taiwan

THz response of graphene-based materials

Nov. 7 (Fri.) Afternoon Session ⅠChair: Jungseek Hwang

F5 14:00 - 14:30Chul-Hong Park

Pusan National University, Korea

Defects and Impurity and Doping in Oxide Semiconductors

F6 14:30 - 15:00Christos PanagopoulosNanyng Technological University, Singapore

Unraveling universal two superconducting domes in

unconventional superconductors

F7 15:00 - 15:30Tsuyoshi Tamegai

University of Tokyo, Japan

Effects of Swift-Particle Irradiations in Iron-based

Superconductors

Nov. 7 (Fri.) Afternoon Session ⅡChair: Tuson Park

F8 16:00 - 16:30Dong Ho Wu

Naval Research Laboratory, USA

High-power, high-resolution terahertz-spectroscopy technologies and their

applications

F9 16:30 - 17:00

Jung-Woo YooUlsan National Institute

of Science and Technology, Korea

Generation and detection of spin currents in carbon-based

compounds

F10 17:00 - 17:30Jiwoo Nam

Taiwan National University, Taiwan

Radio Detection of Ultra-High Energy Neutrinos in Antarctic ice;

ANITA and ARA

POSTER PRESENTERSNo. Name Title

Nov. 5 (Wed.) Poster Session

P1 Jinsu Kim Testing supersymmetric Higgs inflation with non-Gaussianity

P2 Dong Woo Kang Phenomenology in Non-minimal Universal Extra Dimensions

P3 Jongkuk Kim Higgs physics in Universal Extra Dimension model

P4 Seongjin In Sensitivity of Dark Matter Annihilation in the Sun

P5 Minjin Jeong Ice camera system for upgrades to the IceCube Neutrino Telescope.

P6 Alex Hwiwoo Park Performance of Silicon Charge Detector of ISS-CREAM Experiment

P7 Young Hwan Hyun Analytic solution to generalized Teukolsky equations in 5D for brane scalar fields

P8 Minsik Kwag Study of energy levels on 23Mg for the astrophysical 22Na(p,γ)23Mg reaction

P9 Soomi Cha Constraints for the 21Na states through the 24Mg(p, )α 21Na reaction

P10 Eunji Lee Interactive relativistic kinematics code : VISKIN

P11 Minbin KimSpace Environment Test of the X-ray Trigger Telescope (UBAT) for the Gamma-Ray Burst

Space Mission UFFO-pathfinder

P12 Eunjin In Phenomenological features of unitarity in EFT descriptions of low-energy NN scattering

No. Name Title

P13 Wooseong Jo Presidential Election With Spread of Political Opinions Based On Human Migration

P14 Junyoung Son Fabrication and Analysis of Thinfilm Multilayer DNA Nano-Structure

P15 Byeonghoon KimDirected assembly of TiO2 nanoparticles on

artificially designed DNA nanostructure using engineered LacI-STB1 as a linker

P16 Eilho Jung Optical Properties and Analysis of NbCl5(p-type), ZnMg(n-type) Intercalated Graphite

P17 Changzeng YanUV-Vis Light Sensitive Photocatalysts Exploiting SPR Enhanced ZnTe/ZnO/Ag Nanoganoderma

Structures

P18 Hyoungwoo YangGrowth of M2 dominant VO2 thin films on GaN

substrates and Their Electrical and Optical Properties

P19 Hyoungwoo Yang Understanding of Domain Dynamics in Strained VO2 Nanowires

P20 Zahid AliVisible Light Activated Photoelectrochemical

Water Splitting using ZnO/TiO2 based Nano/Micro Hybrid Heterostructure

P21 Imran ShakirHighly Efficient Photocatalysts Exploiting Layer by

Layer Assembled Graphene and Gold Nanoparticles

P22 Lingappan Niranjanmurthi

High Performance Lithium Ion Batteries Employing Polydopamine Coated Graphene/MOS2

Hybrid Nanosheets

P23 Sangheon Park 2D electroride Ca2N as electron transfer layer (ETL) in Organic Photovoltaic

No. Name Title

P24 Simgeon Oh Growth Rate Determined Shape Modulation of ZnO Microwires

P25 Huynh Van Ngoc

Ferroelectric Complementary-Symmetry Metal Oxide Semiconductor Structure Consisting – –of n- and p-type of Si Nanowire Ferroelectric

Field Effect Transistors

P26 Huynh Van NgocSurface Piezoelectricity Dominant High Power Output Nanogenerators Using Ultrathin ZnO

Nanoflakes

P27 Sungmin Woo Surface properties of atomically flat polycrystalline SrTiO3

P28 Seulki Roh Film-fit analysis of Superlattice SrLaTiO/SrTiO

P29 Younghoon OhRelationship between penetration depth and

vortex lattice constant of GdBa2Cu3O7-δ coated conductors

P30 Soohyeon ShinNon-Fermi Liquid behavior in the La-doped

CaFe2As2

P31 Seokbae LeeEnhancement of coupling constant caused by magnetic phase transition in Ni-doped Ba-122

pnictides

P32 Jae Hak Lee Fabrication of MgB2 films at Low-temperature by Hybridphysical-chemical vapor deposition

P33 Pham Van Duong Superconducting property of single-Crystal like MgB2 Thin Films Grown by HPCVD System

P34 Jaekyung Jang A first-principles study for magnetic ground state of antiferromagnet CeAuSb2

P35 Soonbeom Seo Doping effects on the global phase diagram of the heavy-fermion superconductor CeRhIn5

No. Name Title

P36 Sungil KimHeat capacity Measurement of the

pressure-induced superconductor Sn-doped CeRhIn5

P37 Suyoung Kim Effects of La doping in the antiferromagnet CeIn3

P38 Nguyen Thi Hong Trang

Field Emissions of Single Crystalline -Naβ 0.33V2O5Nanowires

P39 Jaeseok HwangLarge scale Synthesis of Large Area Transition Metal Dichalcogenide Atomic Layer by a Simple

Sulfurization

P40 Choongman MoonSub-100nm Pattern Replication Via

Electrohydrodynamic Lithography Exploiting AC Voltage with Resonating Frequency

P41 Soon-Gil Jung Improved critical current density of FeSe by pressure-induced

P42 Dongwon Shin Effects of thermal annealing in the Iron-based Superconductor Ba(Fe1-xCox)2As2 under pressure

P43 Harim Jang Synthesis and study of BaFe2Se3 compounds with low volume fraction superconductivity at Tc=13 K

P44 M. M. AlsardiaElectronic structures and optical properties of

XN (X=Al, Ga, B, In) compounds: Improved density functional theory calculations

P45 Changhyun YiAnalysis of incident-angle dependence of

absorption spectrum of simple metamaterial absorber near 3rd harmonic resonance frequency

P46 Hoang Trong Linh Studies on Metamaterial-based Broadband Perfect Absorbers

P47 Fayyaz Ahmad Crystal Structure of -BiFeOα 3: a First-Principles investigation

ABSTRACT

INVITED TALKS

SKKU International Symposium on Recent Progress in Physics for the 60th Anniversary of Physics Department

Sungkyunkwan University, Suwon, Korea

W1

Reviving Open Inflation

Misao Sasaki

Yukawa Institute, Japan

E-mail address: [email protected]

The scenario of open inflation once popular in the 1990's wasabandoned when our Universe was found to be almost flatabout a decade ago. However, as the precision of observationaldata has increased, the possibility to test the present curvatureparameter of ΩK~0.01-0.001 has become not unrealistic. I argue that open inflation can explain some of recent cosmological data better than others, and it may be a new window to the physics of the Universe at or even before inflation.



W2

Neutrino Physics with IceCube and Its Extensions

Doug Cowen

Pennsylvania State University, USA


We describe how IceCube, the world's largest neutrino observatory, detects neutrinos spanning six orders of magnitude in energy. We highlight its recent discovery of high-energy astrophysical neutrinos, its very competitive measurements in atmospheric neutrino oscillations and its strong limits on the existence of low-mass dark matter. We discuss how we plan to build on the unique advantages provided by the South Pole ice cap to engender future exciting discoveries in these areas.



W3

Dark Matter

Paolo Gondolo

University of Utah, USA


TBA



W4

Searches for Dark Matter and Neutrinoless Double Beta Decay at CUP

Yeongduk Kim

CUP/IBS, Korea


I will describe the R&D activities for the WIMP search experiments using the NaI(Tl) crystals and low temperature detectors. Developments on the scintillating detector for AMoRE experiment and a new underground laboratory plan will be also shown.



W5

Current Results and Prospects of Cosmic Ray Experiments

Eun Suk Seo

Maryland University, USA


Cosmic ray research lies at the intersection of particle physics, cosmology, and astronomy. It focuses on highly relativistic particles produced in the most extreme non-equilibrium environments in nature, e.g., supernova explosions, gamma-ray bursts, or active galactic nuclei. Direct measurements of cosmic rays with satellite or balloon-borne detectors are used for understanding cosmic ray origin, acceleration and propagation. They have also been used to search for exotic sources, such as dark matter and antimatter, and to explore a possible limit to particle acceleration in supernova. Recent results will be presented, and the outlook for existing and future experiments will be discussed.



W6

Spectroscopy of unbound states in unstable nuclei using spin-polarized proton resonance scatteing

Takashi Teranishi

Kyushu University, Japan


In neutron-rich or proton-rich nuclei, low-lying levels are often observed as single-particle neutron/proton resonances, which give us useful information for studying structure, decay and reaction of exotic nuclei. We have performed a series of proton-resonance scattering experiment using low-energy radioactive nuclear beams to investigate resonances in unstable nuclei. I will discuss future plans of an advanced experimental technique for resonance scattering utilizing a spin-polarized proton target.



W7

Facility for low energy nuclear physics at RAON

Young Kwan Kwon

RISP/IBS, Korea


The Rare Isotope Science Project (RISP) has been launched since 2011 in Republic of Korea to build a large-scale accelerator complex, called “RAON” for the RI science. The RAON will be a top world-class RI beam facility including various experimental devices. Among those experimental facilities at RAON, the present status and perspectives of the facility for low energy nuclear physics, named as KOBRA (KOrea Broad acceptance Recoil Spectrometer and Apparatus) will be presented.



W8

Implications of Higgs boson discovery to physics beyond the Standard Model

Nobuchika Okada

University of Alabama, USA


The long-sought Higgs boson in the Standard Model of particle physics was finally discovered at the Large Hadron Collider (LHC) in 2012. We have just started exploring the Higgs sector in the Standard Model towards understanding of the origin of mass. Although the Standard Model is currently known as the best theory in describing elementary particle physics, it has become clear that a number of experimental observations needs physics beyond the Standard Model. Precise measurements of Higgs boson properties at the LHC not only allow us to understand the origin of mass, but also may reveal physics beyond the Standard Model. In this talk, I will first give a brief review on the current status of Higgs physics and then discuss possible implications of the Higgs boson properties measured by the LHC experiments to physics beyond the Standard Model.



W9

Higgs inflation from Standard Model criticality

Yuta Hamada

Kyoto University, Japan


The observed value of the Higgs mass indicates that the Higgs potential becomes small and flat at the scale around 1017GeV. Having this fact in mind, were consider the Higgs inflation scenario proposed by Bezrukov and Shaposhnikov. It turns out that then on-minimal coupling of the Higgs-squared to the Ricci scalar can be smaller ξ than ten. For example, =7 corresponds to the tensor-to-scalar ratio ξr 0.2, which is consistent with the recent observation by BICEP2.≃



W10

Running of the primordial spectra

Jinn-Ouk Gong

APCTP, Korea


TBA



W11

Sneutrino dark matter and its phenomenology

Ki-Young Choi

KASI, Korea


I will talk about the phenomenology of a supersymmetric neutrinophilic Higgs model with a large Yukawa couplings where neutrinos are Dirac particles and the lightest right-handed neutrino is the lightest supersymmetric particle as a dark matter candidate.



T1

Emergent Phenomena at Oxide Interfaces

Harold Y.Hwang

Departments of Applied Physics and Photon Science, Stanford University and SLAC National Accelerator Laboratory, USA

E-mail address: [email protected] Complex oxides are fascinating systems which host a vast array of unique phenomena, such as high temperature (and unconventional) superconductivity, ‘colossal’ magnetoresistance, all forms of magnetism and ferroelectricity, as well as (quantum) phase transitions and couplings between these states. In recent years, there has been a mini-revolution in our ability to grow thin film heterostructures of these materials with atomic precision. With this level of control, a number of new electronic phases have been discovered at their interfaces. Between two insulators, for example, metallic, superconducting, and magnetic states can be induced. In analogy to the rich science and technology that emerged from the development of semiconductor heterostructures, we are using these techniques to create novel low-dimensional states inaccessible in bulk oxides.



T2

Recent progress on graphene growth

Young Hee Lee

1Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University,Suwon, Kyunggi-do 440-746, South Korea

2Department of Physics, Department of Energy Science, Sungkyunkwan University,Suwon, Kyunggi-do 440-746, South Korea

E-mail address: [email protected] Large area graphene is now available from chemical vapour deposition. Nevertheless, the synthesized graphene is mostly polycrystalline with grain boundaries or monocrystalline but the size is limited. Control of graphene grain boundaries is of importance in basic science and technology. Grain boundaries in graphene are formed via the stitching of islands during the initial growth stage, and these boundaries govern transport properties and related device performance. Graphene can be ideally grown from a single nucleation seed, but its growth to large-area graphene can be terminated by several unknown self-limiting growth factors. Another approach is to start with numerous nucleation seeds and allow them to grow and coalesce together to produce large-area graphene. However, graphene grain boundaries are inevitably formed via stitching of graphene flakes, consequently limiting the graphene quality. We will describe several growth factors to achieve monocrystalline graphene growth during CVD, how to confirm grain boundary-free large-area graphene in centimeter scales, and local transport phenomena at the grain boundaries that vary with functionalizations.



T3Charge dynamics of doped BaFe2As2 : Role of

chemical substitution and necessary ingredients for high-Tc superconductivity

Hiroshi Eisaki

National Institute of Advanced Industrial Science and Technology,Tsukuba 3-5-8568, Japan

E-mail address: [email protected] High-Transition-temperature (high-Tc) superconductivity in iron arsenides is usually induced by chemical substitution, or ,doping, into parent compounds. To understand the role of doping, we carried out a comparative resistivity and optical reflectivity measurements on BaFe2As2 with various chemical substitutions. The charge dynamics of parent BaFe2As2 is dominated by incoherent charge carriers, indicative of substantial electron correlation. Electron (Co) and isovalent (P) doping result in transforming the charge dynamics into highly coherent one. On the other hand, charge dynamics remains incoherent for hole (K) doping. In common with any type of doping, high-Tc superconductivity is realized when (1) the normal-state charge dynamics maintains incoherence and when (2) the resistivity associated with the coherent channel exhibits dominant T-linear dependence. This study has been carried out in collaboration with M. Nakajima, S. Ishida, K. Kihou, C.H.Lee, S. Uchida, and A. Iyo.



T4

Superconductivity and Quantum Criticality

S. Seo1, E. Park1, E. D. Bauer2, F. Ronning2, J. D. Thompson2,and Tuson Park1

1Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea2Los Alamos National Laboratory, Los Alamos, NM 87544, USA

E-mail address: [email protected] Magnetic scattering has been known to be detrimental to superconductivity because it breaks the Cooper electron pairs [1, 2]. The discovery of a magnetic critical point inside the pressure-induced superconducting phase of CeRhIn5, however, has posed a strong challenge to this view, questioning if the superconductivity could arise in spite of the QCP or because of the QCP [3-5]. A lack of further explicit examples of a hidden QCP has been laid against the role of quantum critical fluctuations in producing superconductivity. In this presentation, we discuss evidence for superconductivity from quantum fluctuations. We intentionally moved the AFM QCP of CeRhIn5 by a small Sn-doping and found that the pressure-induced superconducting phase moves with the tunable QCPs. The precise control of the superconducting phase by the magnetic QCPs now proves that unconventional superconductivity is produced because of the T=0 K instability in CeRhIn5. These discoveries, though specific to CeRhIn5, are broadly applicable to the SC mechanism of diverse classes of strongly correlated superconductors [6].

[1] B. T. Matthias, H. Suhl, and E. Corenzwit, Phys. Rev. Lett. 1, 92 (1958).[2] A. A. Abrikosov and L. P. Gor’kov, Soviet Physics JETP 12, 337 (1961). [3] T. Park et al., Nature 440, 65 (2006).[4] T. Park et al., Nature 456, 355 (2008).[5] S. Seo et al., Nature Physics 10, 120 (2014)..[6] S. Seo et al., submitted.



F1

Domain Topology and Color Theorems

Sang-Wook Cheong

Rutgers Center for Emergent Materials, Rutgers University, USA


Understanding and controlling domains and domain walls is quintessential for identifying the origin of the macroscopic physical properties of functional materials and exploiting them for technological applications. Domains are associated with different orientations of directional order parameters such as magnetization, polarization, and ferroelastic distortions. Even though the local conditions at, for example, ferroelastic boundaries and liquid crystal defects have been often studied, research on the macroscopic topological constraints in complex domain patterns has been scarce. The four color theorem, which was empirically known to cartographers before the 17th century, states that four colors are sufficient to identify the countries on a planar map with proper coloring (without bordering countries sharing the same color, except for intersections). It is only recently found that this color theorem and its tensorial variation (two-step proper coloring) are directly relevant to global domain topology of a wide range of materials such as multiferroic hexagonal RMnO3 (R-rareearths), ferromagnetic layered Fe1/3TaS2, and rhombohedral ferroelectrics such as BiFeO3 and GeTe. The relevance of color theorems to the domain patterns resembles the relation between the order without periodicity in the Fibonacci sequence, Penrose tiling and the formation of quasicrystals; it is also similar to the way that self-similarity plays the key role in the formation of fractals and dendrites.



F2

Iron Based Superconductors: Discovery and Current Status

Hideo Hosono

Frontier Research Center& Materials and Structures Laboratory,Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku,

Yokohama, Kanagawa 226-8503, Japan

E-mail address: [email protected] Superconductivity is the most clear-cut quantum phenomena observable for bulk materials and has huge potential applications. Search for new superconducting materials has continued to date since the discovery of superconductivity in Mercury (Critical temperature Tc=4.2K) by H. Kamerlingh Onnes in 1911. The largest breakthrough in the history is the discovery of high Tc Cuprates by G. Bednorz and A. Muller in 1986 and the maximum Tc exceeded 77K, boiling temperature of liquid nitrogen in 1987. However, new superconductors with high Tc were not reported since then except MgB2 (Tc=39K) discovered by J. Akimitsu in 2001. We found LaFePO superconductor with Tc=3K in 2006 and LaFeAsO1-xFx with Tc=26K (42K at under high pressure of 5GPa) in early 2008. The latter discovery rekindled the extensive superconductivity research globally, and more than 15,000 papers have been published to now. This excitement originates from disprovement of a widely accepted belief that iron with a large magnetic moment is harmful for emergence of superconductivity and relatively high Tc. Extensive research on iron-based superconductors pushed up the maximal Tc to 56K, which is next to high Tc cuprates and has led to the discovery of more than 50 new iron-based superconducting materials to date. Seen are so many advances in elucidation of superconducting properties and pairing mechanism. In this talk, I introduce a tale to the discovery and show the current status of iron-based superconductors by reviewing progresses in materials, properties, mechanism and the application covering the recent hot topics. Emphases are placed on the unique characteristics arising from multi-orbital nature which totally differs from high Tc cuprates.



F3

Allotropic-like bismuth nanowires at ambient condition

Wooyoung Lee

Department of Materials Science and Engineering, Yonsei University, Seoul, Korea


Allotropy is a fundamental and prevailing concept much studied over the centuries. But although the bulk allotropy of elemental solids is fairly well understood, it remains challenging to produce reliably predicted allotropy that has a different crystal structure and thus accompanies a change in physical properties. This difficulty also applied to widely studied bismuth nanowires: its crystal structure is highly elongated along with c-axis and, as a result, is directly associated with its anisotropic electrical properties. In principle, allotropic transformation from rhombohedral to near-cubic structure in bismuth has been predicted under high pressure-environment, which may potentially provide the ability to control and modulate the electrical band structure. Such effect is promising in that it can reduce the band overlap without size reduction that causes unwanted surface states, reduced mean free path, and effective mass. However, the presence of high pressure for allotropic transformation practically limits the use of allotropic form of bismuth. Here, we demonstrate a ‘nanotropic’ approach that utilizes the lattice mismatch between Bi and Te in core/shell nanowire heterostructure in order to produce allotropic-like bismuth. We find that the strain, caused by such lattice mismatch, of [001]-grown Bi nanowires reduces the atomic linear density (LD) along c-axis that is predicted from theoretical considerations, thus establishing a design rule for strain-induced allotropic change. With our nanowires, interestingly, we measure a thermoelectric figure of merit, ZT, of 0.8 with enhanced Seebeck coefficient, S, primarily owing to the reduced band overlap, according to our density-functional calculations, caused by the decreased LD in the crystal structure.



F4

THz response of graphene-based materials

Hsiang-Lin Liu

Department of Physics, National Taiwan Normal University, Taipei 11677, Taiwan


We present the results of THz absorption measurements of monolayer graphene with molecular doping and four-layer graphene. There are several important findings in this study. First, the THz conductivity of the triazine-doped film consists of free carrier absorption at zero frequency and a disorder-induced finite frequency peak around 4.65 THz. As the temperature is lowered, the Drude plasma frequency (30 THz) decreases, whereas the carrier relaxation time (54 fs) does not show much temperature variation. These scenarios show the semiconducting behavior of the triazine-doped film. Second, a comparison of our measured conductance spectra and the theoretical predictions in turn illuminates the importance of the several scattering mechanisms present in these materials. Third, in a magnetic field, the Drude oscillator strength of four-layer graphene is suppressed and transferred to various finite frequency transitions between the Landau levels. The dramatic increase of the low-frequency transmission is a THz counterpart of the positive magnetoresistance effect. The 300 K magnetodielectric contrast is as large as 60% near 1 THz at 10 Tesla. The results are potentially useful for magnetic memory applications away from the dc limit.



F5

Defects and Impurity and Doping in Oxide Semiconductors

Chul-Hong Park

Pusan National University, Korea


Recently the ZnO-based electronics are extensively investigated.Through the first-principles calculations, the role of the defects and hydrogen impurity will be discussed. The oxides can be easily contaminated by hydrogen, thus the understanding of the role of hydrogen is important. It is well-known that the hydrogen is shallow-donor-like, but recently we showed that the hydroge can play a role of the acceptor, when the Fermi level is close to the conduction band miminum. In addition, the physics of amorphous Zn-O-based amorphous oxides and the role of the O-deficiency will be discussed. The microscopic structure will be discussed based on the effective coordination, and the electronic structure will be understood through the inverse partificipation ratio analysis.



F6

Unraveling universal two superconducting domes in unconventional superconductors

Christos Panagopoulos

Division of Physics and Applied Physics, Nanyang Technological University, Singapore 637371, Singapore

E-mail address: [email protected] Over the past few decades, several new classes of superconductors have been discovered hosting a superconducting (SC) dome when the pristine material is tuned towards a magnetic quantum critical point (QCP). This observation has led to a hypothesis that the formation of a SC dome in the vicinity of a QCP may be instrumental to the mechanism of unconventional superconductivity on the border of magnetism. In this talk, I will present a comprehensive analysis of the phase diagrams across several families of unconventional superconductors including copper-oxides, heavy-fermions, iron-pnictides and iron-chalcogenides, organics, and the recently discovered oxybismuthides. Surprisingly, all these families inherently possess two distinct SC domes, which can be revealed using multiple control parameters. The SC dome at or near the QCP possesses a lower transition temperature (Tc) where as the second SC dome, emerging nearera non-Fermiliquid (NFL) state has a higher Tc and superfluiddensity. Comprehensive analysis reveals that the presence of two SC domes is a universal feature in unconventional superconductors. I will discuss the possible intimate relationship between NFL and higher-temperature superconductivity.



F7

Effects of Swift-Particle Irradiations in Iron-based Superconductors

T. Tamegaia, T. Taena, F. Ohtakea, Y. Suna, H. Inouea, H. Akiyamaa,S. Pyona, H. Kitamurab, T. Kambarac, Y. Kanaic, S. Okayasud

aDept. of Appl. Physics, The University of Tokyo, Japan, bNational Institute of Radiological Sciences, Japan, cRIKEN, Japan, dJapan Atomic Energy Agency, Japan


Since the discovery of superconductivity in iron-based superconductors (IBS), vast amout of reseach activities have been devoted to clarify the mechanism of superconductvity and to demonstrate possible applications of this kind of materials [1]. We have been applying irradiations of swift particles into IBS to study two aspects of superconductvity in this system; (1) pairing symmetry and (2) pinning properties. In a simple superconductor with a single gap and s-wave symmetry, nonmagnetic scatterings do ont affect Tc. This is well-known as the Anderson’s theorem. In an unconventional superconductor with sign-changing order parameters, however, nonmagnetic impurities work similar to magnetic impurities in a conventinal superconductors. In cuprate superconductors, fast suppression of Tc by the introduction of nonmagnetic impurities is unstood in the contecxt of d-wave symmetry with sign-changing order parameter. In IBSs, two kinds of pairing symmetry are intensively discussed, s(+-)-wave due to spin fluctuations [2,3] and s++-wave due to orbita fluctuations [4]. Earlier study of the nonmagnetic impurities suggested that the suppression rate of Tc might be weaker than that expected in s(+-)-wave scenario [5]. The swift-particle irradiation is an ideal way for the introduction of defects since we can follow the variation of Tc in a given crystal as a function of defect density, which is proportinal to the residual resistivity. We have shown that the suppression rate of Tc induced by 3 MeV proton irradiation in Ba(Fe,Co)2As2 is much weaker than that expected for s(+-)-wave superconductors [6]. We also reported similar measurements in high-quality (Ba,K)Fe2As2 single crystal with different doping levels. Similar to the case of

Ba(Fe,Co)2As2, the obtained results do not support the s(+-)-wave superconductivity in (Ba,K)Fe2As2 [7]. Defects created by swift particles irradiations in a superconductor can pin vortices, leading to an enhancement of critical current density (Jc). In cuprate superconductors, significant increase in Jc has been reported by proton [8] and heavy-ion irradiations [9]. We have demonstrated that 200 MeV Au irradiation into Ba(Fe,Co)2As2 is effective in creating columnar defects and enhance Jc by a factor of 5 even at the lowest temperature [10]. Similar effects have been demonstrated by 800 MeV Xe and 1.4 GeV Pb ions [11]. The effect is much more dramatic in (Ba,K)Fe2As2. Jc as high as 6 MA/cm at 5 K has been reported in the case of 1.4 GeV Pb (BΦ=210 kG) [12]. Here, we report that 320 MeV Au irradiation in (Ba,K)Fe2As2 at BΦ=80 kG can enhance Jc up to 10 MA/cm2 at 5 K [13]. Furthermore, magnetic field dependence of Jc becomes very weak and pinning force density at 5 K and 40 kOe reaches 280 GN/m3, which is even larger than 2G-YBCO coated conductors and demonstrate a strong potential of IBS to high-field application. A brief review on the present status of the wire fabrication of IBS will be made.

[1] Y. Kamihara, T. Watanabe, M. Hirano, and H. Hosono, J. Am. Chem. Soc. 130, 3296 (2008). [2] I. I. Mazin, D. J. Singh, M. D. Johannes, and M. H. Du, Phys. Rev. Lett. 101, 057003 (2008). [3] K. Kuroki, S. Onari, R. Arita, H. Usui, Y. Tanaka, H. Kontani, and H. Aoki, Phys. Rev. Lett. 101, 087004 (2008).[4] S. Onari and H. Kontani, Phys. Rev. Lett. 103, 177001 (2009).[5] M. Sato, Y. Kobayashi, S. C. Lee, H. Takahashi, E. Satomi, and Y. Miura, J. Phys. Soc. Jpn. 79, 014710 (2010).[6] Y. Nakajima, T. Taen, Y. Tsuchiya, T. Tamegai, H. Kitamura, and T. Murakami, Phys. Rev. B 82, 220504 (2010).[7] T. Taen, F. Ohtake, H. Akiyama, H. Inoue, Y. Sun, S. Pyon, T. Tamegai, and H. Kitamura, Phys. Rev. B 88, 224514 (2013).[8] L. Civale, A. D. Marwick, M. W. McElfresh, T. K. Worthington, A. P. Malosemoff, F. H. Holtzberg, J. R. Thompson, and M. A. Kirk, Phys. Rev. Lett. 65, 1164 (1990).[9] Civale, A. D. Marwick, T. K. Worthington, M. A. Kirk, J. R. Thompson, L. Krusin-Elbaum, Y. Sun, J. R. Clem, and F. Holtzberg, Phys. Rev. Lett. 67, 648 (1991).[10] Y. Nakajima, Y. Tsuchiya, T. Taen, T. Tamegai, S. Okayasu, and M. Sasase, Phys. Rev. B 80, 012510 (2009).[11] T. Tamegai, T. Taen, H. Yagyuda, Y. Tsuchiya, S. Mohan, T. Taniguchi, Y. Nakajima, S. Okayasu, M. Sasase, H. Kitamura, T. Murakami, T. Kambara, and Y. Kanai, Supercond. Sci. Technol. 25, 084008 (2012).[12] L. Fang, Y. Jia, C. Chaparro, G. Sheet, H. Claus, M. A. Kirk, A. E. Koshelev, U. Welp, G. W. Crabtree, W. K. Kwok, S. Zhu, H. F. Hu, J. M. Zuo, H.-H. Wen, and B. Shen, Appl. Phys. Lett. 101, 012601 (2012).[13] S. Pyon, T. Taen, F. Ohtake, Y. Tsuchiya, H. Inoue, H. Akiyama, H. Kajitani, N. Koizumi, S. Okayasu, and T. Tamegai, Appl. Phys. Express 6, 123101 (2013).



F8

High-power, high-resolution terahertz-spectroscopy technologies and their applications

Dong Ho Wu

Naval Research Laboratory, Washington, DC 20375


A terahertz beam is an electromagnetic wave with a frequency between millimeter-wave and infrared frequencies, typically from 100 GHz to 3 THz. Often, terahertz is referred to as sub-millimeter-wave or far-infrared. A terahertz beam shares the properties of both radio frequencies (RF) and optical beams. Similar to an RF signal, it can penetrate rather deeply into a non-metallic and non-polar material, such as cloth, leather, paper or plastic sheets. In addition, similar to an optical beam, it is highly directional and can be steered or manipulated by optical components, such as lenses, beam splitters, reflectors, and beam-polarizers. Since a large number of molecules’ resonance frequencies, especially rotational modes, lie within terahertz frequencies, terahertz spectroscopy is a highly useful tool for scientific investigation of various materials. At the same time one can use this technology for the identification of unknown or hidden materials. For example, the technology can be used for the detection and identification of illicit drugs, counterfeit medicines, hidden chemicals, explosives and even hidden nuclear materials. Despite these numerous potential applications, at present terahertz spectroscopy is largely underutilized, and it is mostly being used in a laboratory environment. This is in part, but largely, due to the fact that no portable, high-power, high-resolution spectrometer is currently available. We have therefore been developing a number of high-power terahertz sources and high-sensitivity detectors, in order to construct

high-power, high-resolution terahertz spectrometers both – time-domain and frequency-domain terahertz spectrometers. Recently, we demonstrated two different types of terahertz sources: one is a wideband terahertz source, based on terahertz photoconductive antenna technology, and the other is a frequency-tunable terahertz source, based on terahertz parametric oscillator technology. These portable terahertz sources are capable of producing a relatively high-power (> 1 mW), wideband (0.1 3 THz) terahertz beam, or a – high-power (> 1 mW), narrow, tunable terahertz beam over the frequency range from 0.07 3 THz. In addition to the sources, we – have demonstrated three different types of terahertz detectors: a detector based on a metal-semiconductor, field-effect transistor (MESFET) technology, an electro-optic (EO) detector, and an ultra-sensitivity detector based on quantum-dot technology, for which the sensitivities in terms of noise equivalent power (NEP) are 10-9W/(Hz)1/2, 10-13W/(Hz)1/2 and 10-21W/(Hz)1/2, respectively. Recently, by utilizing these terahertz sources and detectors, we have constructed a high-power, high-resolution terahertz spectrometer, and carried out various experiments to understand the resonance spectra of water vapor, chemicals and ionized air. In addition, we have constructed a modified terahertz spectrometer for standoff detection applications. In this presentation ,I will discuss our experimental achievements and progress.



F9

Generation and detection of spin currents in carbon-based compounds

Jung-Woo Yoo

School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Republic of Korea

E-mail address: [email protected] Recent years witnessed increasing research activity in exploiting carbon-based materials as a spin transporting channel, which introduces a new avenue for device integration and functionality. In this talk, I will present application of an organic-based magnetic/non-magnetic semiconductor as an electron spin polarizer/spin transporting layer in the standard spintronic device geometry [1,2]. The application of organic small molecule films as the spin transporting layer has been studied extensively recently. However, conceptual understanding of how the spins are injected into and transport through these organic semiconductor films was still lacking. With careful study on film thickness, temperature, and bias dependencies, significant differences between tunneling and giant magnetoresistance were resolved [1]. In addition, the room temperature organic-based magnet, V(TCNE)x was successfully incorporated into the standard magnetic tunnel junction devices in tandem with LSMO(La2/3Sr1/3MnO3)film [2]. The development of a practical methodology for finely-controlled film growth of an organic-based magnet yielding conformal air stable film morphology is essential to enable a wide range of yet to be realized applications of this hybrid material. I will also present new methodology of film growth of organic-based hybrid magnetic films using molecular layer deposition (MLD). The new hybrid laminate films we developed exhibit major improvement in surface morphology, magnetic and electrical properties, as well as with respect to air-stability.[1] Jung-Woo Yoo, H. W. Jang, V.N. Prigodin, C. Kao, C.B. Eom, and A.J. Epstein, Phys. Rev. B 80, 205207 (2009)[2] Jung-Woo Yoo, C.-Y. Chen, H. W. Jang, C. W. Bark, V. N. Prigodin, C. B. Eom, and A. J. Epstein, Nature Materials 9, 638 (2010).[3] Chi-Yueh Kao, Jung-Woo Yoo, Yong Min, and Arthur J. Epstein, ACS Appl. Mater. & Inter. 4, 137 (2012)



F10

Radio Detection of Ultra-High Energy Neutrinos in Antarctic ice; ANITA and ARA

Jiwoo Nam

Department of Physics and Graduate Institute of Astrophysics,National Taiwan University, Taiwan

E-mai l address: [email protected] We discuss two experiments; ANtarctic Impulse Transient Radio (ANITA) and Askaryan Radio Array (ARA) for studies of ultra-high energy (UHE) cosmogenic neutrinos in Antarctica. These experiments are to detect the coherent Askaryan radio emission from UHE neutrino interactions in the ice. The excellent transparency of the ice in the radio band allows effective solutions to enlarge detection volume. ANITA is a balloon-borne antenna array, which has completed two successful flights since 2006 and is under a preparation of the third flight in December 2014. ARA is a large scale antenna array buried in the South pole ice shelf, now under the initial construction phase. In this report, experimental concepts and designs will be described. Results from existing data and feasible physics topics are also discussed.

ABSTRACT

POSTER PRESENTATION



P1

Testing supersymmetric Higgs inflation with non-Gaussianity

Jinsu Kim

Department of Physics, Sungkyunkwan University, Suwon, Korea


Observational constraints on supersymmetric Higgs inflation typemodels are studied. We show how the backward delta N formalism can be utilized to compute cosmological observables, such as the power spectra, the spectral indices, the tensor-to-scalar ratio and the nonlinearity parameter. In this talk we focus on implications of the nonlinearity parameter that measures the non-Gaussianity of the primordial fluctuations. We find that some parameter of the supergravity Kahler potential is constrained by the Planck satellite results, while other parameters are constrained by phenomenological naturalness.



P2

Phenomenology in Non-minimal Universal Extra Dimensions

T. Flake1, Dong Woo Kang2, K. C. Kong3, S. C. Park2

1Department of Physics, KAIST, Korea2Department of Physics, Sungkyunkwan University, Korea

3Department of Physics and Astronomy, University of Kansas, USA

E-mail address: [email protected] We present a model with universal extra dimensions in the presence of boundary localized kinetic terms for electoroweak gauge bosons. This model can realize that the lightest Kaluza-Klein particle is a mixture of KK B1 and KK W3

1. Depending on boundary localized parameter (rB,rW) the KK dark matter is more like KK Z or KK photon. We show current bounds on (rB,rW) from EWPT by 4-Fermi interaction operators.



P3

Higgs physics in Universal Extra Dimension model

Jongkuk Kim



We examine the Higgs production and decay in the Universal Extra Dimensions model (UED) in light of the recent discovery of the Higgs with 125 GeV mass at the Large Hadron Collider (LHC). The main production mechanism is through the 1-loop induced gluon-gluon fusion, in which top quark and its Kaluza-Klein excitations contribute.



P4

Sensitivity of Dark Matter Annihilation in the Sun

Seongjin In



Dark matter particles captured by the Sun through scattering may annihilate and produce neutrinos, which can escape from the dense solar medium. Current searches are for the few high-energy neutrinos produced in the prompt decays of some final states. However the interactions in the solar medium lead to a large number of pions for nearly all final states, produced in an hadronic shower initiated from the dark matter annihilations. To study this potential neutrino signal, we combine Pythia and Geant4, to model the dark matter annihilation, hadronization and interaction in the Sun’s medium. We inject particles using our simulation framework to model the hadronic shower and evaluate sensitivities for these signals at neutrino detectors. We compare our sensitivities to those achieved by current searches with IceCube and Super-Kamiokande.



P5

Ice camera system for upgrades to the IceCube Neutrino Telescope

Minjin Jeong



IceCube is a km-scale neutrino detector located at the geographic south pole, that consists of 5,160 optical sensors. When neutrinos interact with Antarctic ice they produce light flashes originating from relativistic particles produced in the reaction. IceCube has the benefit of using the ultra-pure ice in the Antarctic as an optical medium to be sensitive to neutrino energies of about 100 GeV to above PeV. IceCube data and analysis have revolutionized the field of particle astrophysics by opening a new window to the sky. At present, projects for next generation of neutrino detectors at the south pole are being considered. We develop a calibration light source and camera system for the Precision IceCube Next Generation Upgrade(PINGU). The camera system will allow us to better understand the ice properties and the local environment of the optical sensors. An overview of the planned extensions to IceCube will be given and the status of the development of the camera system described.



P6

Performance of Silicon Charge Detector of ISS-CREAM Experiment

Alex Hwiwoo Park, Jik Lee, I. H. Park, Jin-A Jeon, H. Y. Lee, G. G. Lee



ISS-CREAM experiment is space borne that will be on International Space Station (ISS). Silicon Charge Detector (SCD) is one of CREAM detector that measures charge constitution of energetic cosmic rays. CREAM which was the NASA Antarctica balloon borne at Antarctica has been successfully done till 9 years so it has another chance to have an experiment on space borne. Particularly SCD has played the key role on CREAM borne. SCD of ISS-CREAM has been changed 2-layer to 4-layer. And all electronics system appropriate for space operation at the International Space Station. SCD is already developed for ISS and it passed thermal & vacuum test and vibration test that NASA requires for space qualification. We will present about electronics performance with thermal & vacuum test and vibration test and source test with Strontium-90 which is a radioactive isotope of strontium.



P7

Analytic solution to generalized Teukolsky equations in 5D for brane scalar fields

Young Hwan Hyun


E-mai l address: [email protected]

We show that the generalized Teukolsky equations for rotating 5D black holes for brane fields is equivalent to the confluent Heun’s equation. The equation is further reduced to the form of spheroidal equation for scalar fields and analytically solved. The full analytic expressions for greybody factors for scalar fields is finally obtained as a consequence.



P8

Study of energy levels on 23Mg for the astrophysical 22Na(p,γ)23Mg reaction

M. S. Kwag,1 K. Y. Chae,1,* S. H. Ahn,2 D. W. Bardayan,3 S. M. Cha,1

K. A. Chipps,4 J. A. Cizewski,5 M. E. Howard,5 A. Kim,1 R. L. Kozub,6 E. J. Lee,1

B. Manning,5 M. Matos,777 P. D. O’Malley,5 S. D. Pain,8 W. A. Peters,9

S. T. Pittman,8 A. Ratkiewicz,5 M. S. Smith,8 and S. Strauss5

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea,2Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA,

3Department of Physics, Notre Dame University, Notre Dame, Indiana 46556, USA,4Department of Physics, Colorado School of Mines, Golden, Colorado 80401, USA,

5Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA,6Department of Physics, Tennessee Technological University, Cookeville, Tennessee 38505, USA,

7Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA, 8Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA,

9Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831, USA

E-mail address: [email protected] The destruction of 22Na ejecta in nova explosion strongly depends on the 22Na(p,γ)23Mg reaction. The spins and parities of energy levels in 23Mg above proton threshold (7.581 MeV) is crucial to calculate 22Na(p,γ)23Mg reaction. Although many studies worked on these energy levels, many uncertainties of the spins are still remained. To improve understanding of these properties, the 24Mg(p,d)23Mg transfer reaction has been studied at Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory using 31 MeV protonbeams. Details of the experiment and current results of the analysis will be presented.



P9

Constraints for the 21Na states through the 24Mg(p,α)21Na reaction

S. M. Cha,1 K. Y. Chae,1,* S. H. Ahn,2 D. W. Bardayan,3 K. A. Chipps,4

J. A. Cizewski,5 M. E. Howard,5 A. Kim,1 R. L. Kozub,6 M. S. Kwag,1 E. J. Lee,1

B. Manning,5 M. Matos,777 P. D. O’Malley,5 S. D. Pain,8 W. A. Peters,9

S. T. Pittman,8 A. Ratkiewicz,5 M. S. Smith,8 and S. Strauss5

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea,2Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA,

3Department of Physics, Notre Dame University, Notre Dame, Indiana 46556, USA,4Department of Physics, Colorado School of Mines, Golden, Colorado 80401, USA,

5Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA,6Department of Physics, Tennessee Technological University, Cookeville, Tennessee 38505, USA,

7Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA, 8Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA,

9Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831, USA

E-mail address: [email protected] The 20Ne(p,γ)21Na reaction is a part of Ne-Na cycle which is believed to be responsible for the nucleosynthesis of Ne and Na isotopes. Since the reaction proceeds through the energy levels of 21Na above the proton threshold at 2.431 MeV, the properties of those levels are important to estimate the reaction rate at stellar temperatures. For constraining the spins of energy levels in 21Na, the 24Mg(p,α)21Na reaction has been measured at the HRIBF of the Oak Ridge National Laboratory by using 31 MeV proton beams and 24Mg solid targets. Recoiling particles were detected by a segmented silicon detector α array at 16 angles simultaneously. Angular distributions of the first four excited states including ground state in 21Na are compared with the distorted wave Born approximation (DWBA) calculations. Details of the experiment and the current stage of the data analysis will be discussed.



P10

Interactive relativistic kinematics code : VISKIN

E. J. Lee,1 K. Y. Chae,1 D. W. Bardayan,2 and S. Graves3

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea,2Department of Physics, Notre Dame University, Notre Dame, Indiana 46556, USA,

3Department of Physics, Tennessee Technological University, Cookeville, Tennessee 38505, USA


Transfer reactions are often very useful to study properties of energy levels of nuclei. Since transfer reaction measurements may populate many energy levels in a single run, internal calibrations are critical to analyze excitation energies of populated levels. Relativistic kinematics calculations are needed to perform the internal calibrations. Existing codes are, however, somewhat limited in that the calculations should be done for each energy level separately. To overcome this inconvenience, the VISualized KINematics (VISKIN) has been developed by using an computer language Java. Details of the program and the application to the 24Mg(p,α)21Na experimental data will be presented.



P11Space Environment Test of the X-ray Trigger

Telescope (UBAT) for the Gamma-Ray Burst Space Mission UFFO-pathfinder

M. B. Kim1, Y. Lee1, J. Ripa1, S. Jeong2, J. Lee1, I. H. Park1

1Dept. of Physics, Sungkyunkwan University, Korea 2Dept. of Stellar Physics, Instituto de Astrofísica de Andalucía (IAA-CSIC), Spain

E-mail address: [email protected] Ultra-Fast Flash Observatory (UFFO)-pathfinder aboard Lomonosov satellite is developed to observe the early optical afterglow of Gamma-ray Burst (GRB). It is foreseen to launch on 2015. UFFO-pathfinder is composed of UV/Optical telescope, which is called Slewing Mirror Telescope (SMT) and UFFO Burst Alert & Trigger Telescope (UBAT) for GRB trigger and early localization. UBAT is built to cover 90*90 degree of sky and localized it with 10 arcmin accuracy using coded mask technique. UBAT detector is made up of 36 YSO scintillation crystal having 64 channel arrays, Multi-Anode Photomultipliers (MAPMTs), analog and digital electronics. In this conference, we will report its important performances which are confirmed recently through ground calibration of UBAT X-ray detector and coded mask. We confirmed its uniform response overall detector plane and low X-ray sensitivity up to ~5keV.



P12

Phenomenological features of unitarity in EFT descriptions of low-energy NN scattering

Eunjin In



In effective field theory descriptions of low-energy two nucleon systems, a regulator is needed to remove divergence in loop calculations or in solving the Lippmann-Schwinger equation. Typical momentum cutoff regulators, however, violates the unitarity which is one of the most important properties of the S Matrix. At next-to-leading order, we study the consequences of the unitarity by evaluting 1S0 np phase shift with five sets of regulators, some of which preserve the unitarity and the others do not.



P13

Presidential Election With Spread of Political Opinions Based On Human Migration

Woo Seong Jo



The voter model has been studied in various systems to understand how opinions spread. Recently, several studies showed that election results can be addressed by applying the voter model with commuter flow. However, political opinions of individuals can be strongly affected by their birthplaces as well as where they are. We apply the voter model to presidential election in South Korea from 1971 to 2012, considering the annual inter-province flow of migration. Keeping information of birthplace, agents change their political opinions with given probability which is assigned by birthplace. We compute the probability of changing opinions, comparing the outcome from real elections with simulation results. We expect that the long-term evolution of the probability may show the changes in province-wise political opinions.



P14

Fabrication and Analysis of Thinfilm Multilayer DNA Nano-Structure

Junyoung Son1,#, Junwye Lee2,#, Anshula Tandon2,#, Byeonghoon Kim2, Sanghyun Yoo1, Sung Ha Park1,2

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea2Sungkyunkwan Advanced Institute of Nanotechnology (SAINT),

Sungkyunkwan University, Suwon 440-746, Korea

E-mail address: wiseosho@gmai l.com DNA has been employed as a self-assemblable biomaterial for the construction of periodically patterned nanostructures by exploiting Watson Crick complementarity. Here we demonstrate three dimensional –tile based multilayer DNA nanostructures incorporating two design strategies; vertical growth and horizental layer stacking using substrate assisted growth. To achieve this we designed a periodically holed DDX template structure which is exploited to examine the growth of multilayer structures both in vertical and horizontal directions. For vertical growth, The traditional 2-D DNA lattice structure was seeded and grown vertically from periodic holes of DDX template structure. In horizental stack, DDX layer was stacked under binding of connector tile between each layer. Albeit the successful formation of multilayers in both events, it was clearly evident from the AFM data that the DDX layer growth in horizontal stacking approach was considered more superior as compared to the vertical growth of the DX layers, in aspects of uniformity and layer size, and discreteness. Specially, newly designed DDX template layer gave parallel arrangement between each domain under Substrate Assisted Growth. This kind of novel and intriguing arrangement of layers suggests a possible role of this design scheme in construction of other periodic structures.



P15Directed assembly of TiO2 nanoparticles on artificially

designed DNA nanostructure using engineered LacI-STB1 as a linker

Byeonghoon Kim#, Ji-Ryang Jang#, Sung Ha Park,* and Woo-Seok Choe*

Department of Nano Science and Technology, Sungkyunkwan University, Suwon 440-746, Republic of Korea

E-mail address: [email protected] Sequence programmable DNA can serve as a building component to construct artificially designed DAN nanostructure with predictable nano-scale precision. In this study, a template comprising double-crossover (DX) DNA lattice and engineered LacI-STB1 protein was used as a nano-tweezer to achieve 2D nano-array of TiO2 nanoparticles (NPs) [1]. First, LacI-STB1/DX scaffold was fabricated by intrinsic interaction between the engineered protein and site specific lacO embedded DX DNA tile. Subsequently, precise positioning of TiO2 NPs was directed by engineered LacI-STB1 containing dual binding pockets: one for lacO duplex and the othe for TiO2 at N- and C-terminus of LacI-STB1, respectively [2]. Our approach demonstrated in this study provides a novel strategy for bottom-up fabrication of nanostructure by harnessing DNA as a scaffold and protein as a linker to pinpoint NP anchorage.

Figure 2. Scheme of DNA-protein-nanoparticle conjugation.

[1] Design and self-assembly of two-dimensional DNA crystals. Nature 1998, 394, 539-44.[2] Engineering LacI for self-assembly of inorganic nanoparticles on DNA scaffold through the understanding of LacI binding to solid surfaces. Adv. Funct. Mater. 2009, 19, 1186-92.



P16

Optical Properties and Analysis of NbCl5(p-type), ZnMg(n-type) Intercalated Graphite

Eilho Jung1, Seokbae Lee1, Seulki Roh1 ,Xiuqing Meng2, Sefaattin Tongay3, and Jungseek Hwang1

1Department of Physics, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea2Research Center for Light Emitting Diodes (LED), Zhejiang Normal University, Jinhua 321004, China 3Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA

E-mail address: [email protected] In this study we used ZnMg alloys and NbCl5 as new intercalants and focused on infrared properties of the intercalated graphite compounds obtained with these two intercalants. NbCl5 is intercalated in Graphite for p-type doping and ZnMg is intercalated in Graphite for n-type doping. We measured reflectance spectra of our intercalated graphite samples in far- and mid-infrared range (50~7000cm-1). We obtained the optical conductivity and the dielectric function from the measured reflectance using a Kramers-Kronig analysis. We obtained the dc conductivity data and the plasma frequencies out of the conductivity and dielectric function. Further analyses allow us to obtain the plasma frequencies of charge carries from the dielectric function and the information of the electronic band structures from the optical conductivity. Our study also confirm recent calculated band structures of NbCl5 and ZnMg intercalated graphite compounds by using a density functional theory.



P17

UV-Vis Light Sensitive Photocatalysts Exploiting SPR Enhanced ZnTe/ZnO/Ag Nanoganoderma Structures

Changzeng Yan and Dae Joon Kang

Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea

One-pot growth of ZnTe (p-type)/ZnO (n-type) layer on Ag nanowires was achieved by wet chemistry method. The novel designed hybrid nanostructure shows excellent full solar spectra photocatalytic property which degrades more than 90% Toluidine Blue O (TBO) dye within 20 minutes. The surface plasma resonance effect and p-n junction synergistically contribute to the efficient degradation.



P18

Growth of M2 dominant VO2 thin films on GaN substrates and Their Electrical and Optical Properties

Hyoungwoo Yang and Dae Joon Kang



We report on the growth of high-quality M2 dominant VO2 thin films epitaxially on GaN substrates by RF sputtering and their unique metal-insulator transition (MIT) properties. The electrical and optical properties in VO2 thin films grown on GaN exhibit metal insulator transition behaviors which are markedly different from those conventional VO2 thin film results reported elsewhere. Thermally-driven MIT was observed with nearly four orders of magnitude change in resistance values across the MIT with transition temperatures of 78 °C and 72°C on heating and cooling, respectively. Voltage-driven hysteretic MIT was also observed at room temperature at threshold voltage of 1.6 V for ~ 100 nm thick VO2 lms. We further compared fithe properties of VO2 thin lms grown under identical conditions on fic-plane sapphire substrate. The VO2 thin films grown on GaN substrate showed higher crystallinity and larger resistance change across MIT compared to those grown on c-cut sapphire substrate. This study may lead to a unique opportunity to better understand the mechanism of electrical and magnetic phase transition in VO2.



P19

Understanding of Domain Dynamics in Strained VO2 Nanowires

Hyoungwoo Yang and Dae Joon Kang



Here, we demonstrate that the strain in bent VO2 nanowires may have a strong effect on the appearance and thermal stability of metastable M2 phase as well as on the spatial distribution of insulating and metallic domains during the phase transitions. We found that the strain induced in bent VO2 nanowires during the growth affects greatly the thermal stability of M2 phase at room temperature, which is an evident up-shift of phonon modes from 615cm-1 (M1) to 640cm-1 (M2) and visualized by confocal Raman spectroscopy. Furthermore, we employed the electrical transport studies to understand the electrical properties by scanning out the resistivity difference originated in M1 and M2 phase distribution associated with strain. The result indicated clearly that the phase distribution is consistent with the strain distribution showing that the metal-insulator transition in VO2 nanowires can be strongly affected by subtle interplay between the strain and domain dynamics. The capability to engineer phase distribution with strain lends insight into correlated electron materials in general, and opens opportunities for designing and controlling the insulating phases of VO2 for practical device applications.



P20Visible Light Activated Photoelectrochemical Water Splitting using ZnO/TiO2 based Nano/Micro Hybrid

Heterostructure

Zahid Ali, Imran Shakir and Dae Joon Kang


We report on a novel approach for the design and synthesis of a ZnO and TiO2 based heterostructure in which vertically oriented ZnO nanowires are grown on freely suspended TiO2 microspheres so as to utilize efficient light scattering and heterojunction effects for water splitting under visible light irradiation. The synthesis approach presented here has several unique design benefits, including tuning of both the exposed surface area of ZnO and the interface between ZnO and TiO2 to enhance the photocatalytic water splitting via heterojunction effect, enhanced electron transport through a highly connected network of ZnO nanowires, and efficient light scattering response over a large spectrum of sunlight. The synthesized structure has shown significantly lower saturation and onset potential compared to ZnO nanowire arrays, demonstrating its potential for reducing the applied bias required to achieve maximum photocurrent.



P21

Highly Efficient Photocatalysts Exploiting Layer by Layer Assembled Graphene and Gold Nanoparticles

Imran Shakir, Muhammad Shahid, Zahid Ali and Dae Joon Kang


Tin oxide coated molybdenum oxide nanowires (SnO2/MoO3) is synthesized by a combination of hydrothermal and wet chemical routes. The electrochemical capacitance properties of the SnO2/MoO3 core shell composite nanowires are measured by cyclic voltammetry (CV) and galvanostatic charge discharge method in 1 M Na– 2SO4 aqueous solutions. The results showed that specific capacitance of SnO2/MoO3 core shell composite nanowires is 295 F g 1− , which is much higher than the specific capacitance of pure individual MoO3 (69 F g 1− ) and SnO2 (96.6 F g 1− ). Moreover the synthesized core shell composite nanowires has also exhibited excellent long-term cycling stability (only 3 % loss of its initial specific capacitance after 1000 cycles) which may lead to its multifarious usage in high-performance energy storage devices for future potential applications.



P22High Performance Lithium Ion Batteries Employing

Polydopamine Coated Graphene/MOS2 Hybrid Nanosheets

Lingappan Niranjanmurthi and Dae Joon Kang


Ultra-thin 2D MOS2 nanosheets have been extensively studied as an anode material for lithium ion batteries due to its low-cost, excellent specific capacity and high power density. Despite the significant advantages, however, MoS2 still suffers from poor cycling stability, which arises from the dissolution of intermediate polysulphide ions in the electrolyte. Here, we demonstrate the synthesis of robust electrode network toward improving the cycling stability of MoS2 based anode materials. The graphene/MoS2 hybrid nanosheets are synthesized via a simple hydrothermal method. The as-prepared nanosheets are subsequently coated by thin polydopamine layer. As a result, the designed electrode exhibits a remarkable specific capacity, high rate capability and high power density. More importantly, the electrode shows an outstanding cycling stability, owing to the polydopamine coating, which protects the polysulphide dissolution and stabilizes the whole electrode during cycling.



P23

2D electroride Ca2N as electron transfer layer (ETL) in Organic Photovoltaic

Sangheon Parkab, Jae Yeol Hwangc, and Jungseek Hwanga

aDepartment of Physics, Sungkyunkwan university(SKKU), KoreabDivision of Advanced Materials, Research Center for Energy Materials, Korea

Research Institute of Chemical Technology(KRICT), KoreacInstitute for Basic Science (IBS), Sunkyunkwan University (SKKU), Korea

E-mail address: [email protected] For the first time we have applied 2D electride, Dicalcium Nitride (Ca2N) to an Organic Photovoltaic (OPV) device as electron transfer layer (ETL) material. In general, Calcium (Ca) and Lithium Fluoride (LiF) were used as electron transfer materials in order to help charge transfer to the cathode electrode in OPV devices. Recently, Ca2N is the first reported two dimensional electride which has electrons as its anions. This new material can be used as an electro-active material [1]. The wok function of Ca2N is quite similar to these of LiF (2.8 eV) and Ca (2.9 eV), but slightly high (2.6 eV). Therefore one may expect that Ca2N, instead of conventional materials, can be applied to OPV devices and can increase both the open-circuitvoltage (Voc) and the short-circuit current density (Jsc) due to the plentiful electrons in Ca2N. In this experiment, we used the commercial photovoltaic material P3HT [Poly(3-hexylthiophene)] and PTB7 (PolymerThieno[3,4-b]thiophene/benzodithiophene) as donor and PC61BM (Phenyl-C61-ButyricacidMethylester) and PC71BM (Phenyl-C71-butyricacidmethylester) as acceptor, respectively. Our results show that the performance of Ca2N applied solarcell devices is almost equal to or slightly higher than that of the reference device. This indicates that Ca2N can be a new electro active material and be successfully applied to other optoelectronic devices.

[1] Kimoon Lee, SungWng Kim, Yoshitake Toda, Satoru Matsuishi & Hideo Hosono, “Dicalcium nitride as a two-dimensional electride with an anionic electron layer”, Nature, 2013, 494, 336



P24

Growth Rate Determined Shape Modulation of ZnO Microwires

Simgeon Oh and Dae Joon Kang



We demonstrate that the careful control of the growth rate allows us to modulate cross-sectional shapes of ZnO microwires. The ZnO microwires are successfully synthesized into hexagonal or rhombus shape in a controllable way by using a CVD method. Two different shapes of ZnO microwires show different growth directions and it was confirmed by piezoelectric polarization. Raman and XRD result indicates that two different shapes of ZnO MWs have good crystalinity. In addition, we found that the growth rate of ZnO microwire and PL spectra shows subtle dependency indicating that the defect concentration affects the growth direction of ZnO microwire. It was found that ZnO microwires with different cross-sectional shapes have distinctive optical and electrical properties. We expect these results will pave the way for ZnO application devices.



P25Ferroelectric Complementary-Symmetry

Metal Oxide Semiconductor Structure Consisting of – –n- and p-type of Si Nanowire Ferroelectric Field

Effect TransistorsHuynh Van Ngoc, Jae Hyun Lee, Dongmok Hwang and Dae Joon Kang



Solid state disk (SSD) or nonvolatile memory chips in the modern potable electronic devices is an indispensable part where ferroelectric memory could have a great potential to be used for this application. Especially, building a memory with low power consumption is critical for energy saving and long term use of these devices. Here we report a ferroelectric complementary-symmetry metal oxide semiconductor – –(F-CMOS) structure consisting of n- and p-type of Si nanowire ferroelectric field effect transistors (FeFETs) with extremely low power consumption and long retention time desirable for ferroelectric memory device. Further, we overcome the interfacial layer problem with Si conducting channel FeFET by incorporation of poly(vinylidene fluoride-trifluoroethylene) as an organic ferroelectric-gate and Omega-shaped-gate for enhancement of device performance. We successfully fabricated high performance F-CMOS nonvolatile memory cells. Our memory devices exhibits excellent memory characteristics with ultra-low reading states power dissipation ( 0.1 pW), a large ≤ modulation in channel conductance between ON and OFF states exceeding 105, a long retention time of over 5x104 sec while maintaining an VON/VOFF ratio higher than 103. This result offers a viable way to fabricate a high performance, high density and low power consumption nonvolatile memory device using a low temperature fabrication processing technique, which makes it suitable for flexible electronics.



P26

Surface Piezoelectricity Dominant High Power Output Nanogenerators Using Ultrathin ZnO Nanoflakes

Huynh Van Ngoc and Dae Joon Kang



We report a novel and simple synthetic route to obtain ultrathin ZnO nanoflakes (NFs) of less than 10 nm in thickness, which can be grown on arbitrary substrates using an aqueous precipitation method at room temperature. Based on a rational design, a facile route to achieve a high output power nanogenerators (NGs) that composed of ZnO NFs is demonstrated. This NG exhibits a short-circuit current density of 57 A/cmμ 2, a peak open-circuit voltage of 110 V, which are the best values recorded among all NGs based ZnO nanostructures reported in the literature. These results are further verified using different vibration sources, such as a periodic pounding of a heavy object and a sound wave. Nanogenerators based ZnO nanowires are also fabricated for comparison. Moreover, different interface mechanisms are experimentally compared to maximize the piezoelectric output power (such as thin insulating layers, a p-n junction, and hybridization of two piezoelectric materials). The output power of our NG, with area of 1 x 1 cm2, can be directly used to instantly turn on 20 commercial light-emitting diodes (LEDs) without any use of an energy storage system. We believe that, the high surface area, and especially the strong domination in surface piezoelectricity effects originated from unique morphology of ultrathin nanoflakes, which contributed to this exceptional performance.



P27

Surface properties of atomically flat polycrystalline SrTiO3

Sungmin Woo1, Hoidong Jeong1, Sang-A Lee1,2, Hosung Seo3,Morgane Lacotte4, Adrian David4, Hyun You Kim5, Wilfrid Prellier4,

Yunseok Kim3, Woo Seok Choi1*

1Department of Physics, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Korea2Insitute of Basic Science, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Korea3School of Advanced Materials Science and Engineering, Sungkyunkwan University, Korea

4Laboratorie CRISMAT, CNRS UMR 6508, ENSICAEN, Normandie Universite, France5Department of Nanomaterials Engineering, Chungnam National University, Korea

E-mail address: [email protected] Poly-crystal materials provide us an opportunity to investigate intriguing physical phenomena including electronic and ionic conduction at the grain boundaries, phonon scattering, and domain dynamics. In order to understand the properties of poly-crystals, a comparison study between single- and poly-crystalline samples with the same quality, e.g., stoichiometry, crystallinity, thickness, etc, is necessary. In particular, poly-crystalline transition metal oxides (TMO) provide various interesting properties compared to single-crystalline TMOs. To fabricate a poly-crystalline TMO thin film using epitaxy, we prepared atomically flat poly-crystalline SrTiO3, and investigated the surface properties. Since poly-crystal SrTiO3 has many different orientations and therefore dissimilar surface energy, different etching and annealing condition might be required to obtain atomically flat surfaces. Using careful surface treatment, we could achieve atomically flat polycrystalline SrTiO3 surface at the optimum condition window in which three experimental variables (etching time, annealing temperature, and annealing time) result in excellent surface condition for crystallographic orientations exemplified as (100), (110), (111). Using Atomic force microscopy, Kelvin probe force microscopy, and Electron backscattering diffraction, we further characterize the relationship between the crystallographic orientation and surface energy of atomically flat poly-crystalline SrTiO3.



P28

Film-fit analysis of Superlattice SrLaTiO/SrTiO

Seulki Roh1, Minsu Choi2, Seokbae Lee1, Sanghun Park1, Jaichan Lee2, and Jungseek Hwang1

1Department of Physics, Sungkyunkwan University, Suwon, 440-746, Korea2School of Advanced Material Science and Engineering, Sungkyunkwan University,

Suwon, 440-746, Korea

E-mail address: [email protected] Since the perovskite oxide material provides high dielectric constant, it has been a promising material to be used as storage devices. Here, we investigated SrTiO3 (STO) based superlattice materials to understand their characteristic properties. Three samples were prepared differing the number of STO layers between Sr0.75La0.25TiO3 (SLTO) layers. We named the three samples as 1/1. 1/3 and 1/5. Our measurement was focused on optical response in a wide spectral range from FIR to UV. Using FTIR and Monochromatic spectrometers, reflectance spectra were measured. A film-fit analysis was used to get superlattice film only properties. Using relations between optical constants, we could obtain the optical conductivity. Compared with Ellipsometry data, 1/1 sample showed a Drude mode, which is also consistent with resistivity data. On the other hand, our 1/3 sample showed metallic behavior at 300K. We can expect a Metal-Insulator-Transition (MIT) around 45K in the 1/3 sample based on the resistivity data.



P29

Relationship between penetration depth and vortex lattice constant of GdBa2Cu3O7-δ coated conductors

Y.H. Oha, Soon-Gil Junga, N. H. Leea, S. Ohb, C. H. Leeb, Soon-Mi Choic, Sang-Im Yooc, W. N. Kanga*

aBk21 Physics Division and Department of Physics, Sungkyunkwan University, Suwon 440-746, Republic of Korea

bMaterial Research Team, National Fusion Research Institute, Daejeon 305-333, Republic of Korea

cDepartment of Materials Science & Engineering, and Research Institute of Advanced materials(RIAM), Seoul National University, Seoul 151-744

E-mail address: [email protected] GdBCO has been regarded as a potential material for large scale application due to its high critical temperature (Tc) and high critical current density (Jc). We measured M-H curves GdBa2Cu3O7-δ coated conductors (CCs) over a wide range of temperatures from 10 to 85 K by Using magnetic property measurement system (MPMS). The vortex-vortex distance is considered in this study through an anlaysis of the critical current density (Jc) and the flux pinning force density (Fp). We can observed there is a relation between the penetration depth ( ) and the vortex lattice constant (aλ 0). The Jc’s are normalized to the maximum critical current density (Jc) at each temperature, and the inter-vortex distances (a0) are divided by the penetration depth ( ) λat each temperature. The Jc’s start to decrease at a0/ = 2 and the λ curvatures of the Jc’s change again around a0/ = 0.5. We describe λ these features by considering the relation between the inter-vortex distances and the vortex-vortex interaction.



P30

Non-Fermi Liquid behavior in the La-doped CaFe2As2

Soohyeon Shin+, Soon-Gil Jung, TusonPark*



Since the discovery, Fe-based superconductors have attracted great interest because of its high superconducting transition temperature and the possibility for unconventional nature of superconducting mechanism1-3. In this study, we report successful synthesis of the Fe-based high-temperature superconductor Ca1-xLaxFe2As2, which is formed in tetragonal (I4/mmm) structure. Electrical resistivity was performed under quasi-hydrostatic pressure up to 22.5 kbar. Superconducting phase appears at Tconset=43.5 K and is enhanced by external pressure up to 48.8 K at an optimal pressure of 14.8 kbar (=Pc), showing a dome shape in the temperature-pressure (T-P) phase diagram. In the vicinity of the optimal pressure, temperature dependence of the resistivity shows a T linear behavior and the residual resistivity value is – maximal at Pc, indicating a strange metallic behavior in the normal state. Anomalous enhancement of electron scattering is also revealed as a funnel-shape contour of the resistivity in the T-P plane near Pc, indicating that additional source electron scatters is present. These results are consistent with a presence of a hidden quantum critical point inside the superconducting dome of La-doped Ca122.

Keywords ; Ca1-xLaxFe2As2, unconventional superconductor, quantum fluctuation

[1] K. Hashimoto et al. A sharp peak of the zero-temperature penetration depth at optimal composition in BaFe2(As1-xPx)2. Science 336, 1554 (2012).[2] Masahito Yoshizawa et al. Structural Quantum Criticality and Superconductivity in Iron-Based Superconductor Ba(Fe1-xCox)2As2. Journal of the Physical Society of Japan 81, 024604 (2012).[3] James G. Analytis et al. Transport near a quantum critical point in BaFe2(As1-xPx)2. Nature. Phys. 10, 194-197 (2014).



P31Enhancement of coupling constant caused by magnetic phase transition in Ni-doped Ba-122

pnictidesSeokbae Lee1, Kiyoung Choi2, Eilho Jung1, Seulki Rho1, Soohyeon Shin1,

Tuson Park1, Jungseek Hwang1

1Department of Physics, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746, Republic of Korea

2Department of Physics, Seoul National University, Seoul 161-742, Republic of Korea

E-mail address: [email protected] We studied two BaFe2-xNixAs2 (Ni-doped Ba-122) single crystals at two different doping levels (underdoped and optimally doped) using an optical spectroscopic technique. We analyze the data with two different approaches so-called two-component and one-component analyses. We observed that the enhancement of the coupling constant, obtained from the electron-boson spectral density function, takes place below the magnetic transition temperature in our underdoped sample. We find that only electron carriers in the electron pocket in the Fermi surface contribute to the magnetic phase transition. We also find that the temperature and doping dependent properties of the electron-boson spectral density are the same as those of cuprates which indicates that these two high temperature superconductors may have the same mechanism for the superconductivity. These new findings can give an insight to figure out the superconducting mechanism of relatively new high temperature superconductors, pnictides.



P32

Fabrication of MgB2 films at Low-temperature by Hybrid physical-chemical vapor deposition

Jae Hak Lee, Won Kyung Seong, Mahipal Ranot, Won Nam Kang*

Sungkyunkwan University, Suwon 440-746, South Korea


We have fabricated highly c-axis oriented MgB2 films on Al2O3

substrates at low temperatures (420 ~500 ) by hybrid ℃ ℃physical-chemical vapor deposition (HPCVD). Crystallographic investigation of the films was performed by X-ray diffractometer (XRD) and scanning electron microscope (SEM). Their grain size and the shape of the grain were affected by the growth temperature, which had influence on the superconducting properties, such as superconducting transition temperature, critical current density, and upper critical fields. The technique of low-temperature fabrication of MgB2 films is an important for the MgB2 coated conductor, because the low-temperature growth has merits in industry and for technological applications of superconductivity.

Kewords: MgB2 film, HPCVD, Low temperature



P33

Superconducting property of single-Crystal like MgB2 Thin Films Grown by HPCVD System

Pham Van Duong, Mahipal Ranot and Won Nam Kang*

BK21 Physic Division and Department of Physic, Sungkyunkwan University, Suwon 440-746, Republic of Korea

E-mail address: [email protected] Single-crystal like MgB2 thin film was grown on (000l) Al2O3 substrate by using hybrid physical chemical vapor deposition (HPCVD) system. Single –crystal properties were studied by X-ray diffraction (XRD) and the full width at half maximum (FWHM) of the (0001) MgB2 peak is 0.15°, which is very close to that has been reported for MgB2 single-crystal. It indicates that the crystalline quality of thin film is good. The epitaxial growth was confirmed by performing -scan on the film. Resistivity dependence on temperature was ϕinvestigated by physical property measurement system (PPMS) in various applied fields from 0 to 9 T. The upper critical fields were determined from PPMS data for the fields applied parallel and perpendicular to the a-b plane of the film. The anisotropy ratio = γ !"#

⫽$%(0)/!"#⫠$% was estimated to be 2.5, which is very comparable with that of MgB2 single-crystals [1]. The smooth surface was observed for the thin film by SEM analysis, which makes it well qualified for device applications. In addition, the thin film shows a high critical temperature (Tc) of 40.4 K with a sharp superconducting transition width of 0.2 K, and a high residual resistivity ratio (RRR=21), it reflects that MgB2 thin film has a phase pure structure.

Keywords : MgB2 thin film, Single-crystal, HPCVD

[1] M. Xu, H. Kitazawa, Y. Takano, J. Ye, K. Nishida, H. Abe, A. Matsushita, N. Tsujii and G. Kido, “Anisotropy of superconductivity from MgB2singlecrystals”, Appl. Phys. Lett., 79, p. 2779, Oct. 2001.

This work was supported by Mid-career Researcher Program through NRF grant funded by the Ministry of Education, Science & Technology (MEST) (No. 2010-0029136).



P34

A first-principles study for magnetic ground state of antiferromagnet CeAuSb2

JaeKyung Jang and JooYull Rhee

Department of physics, Sungkyunkwan University, Suwon, 440-746, Korea


A Ce-based compound CeAuSb2, one of the heavy-fermion materials which contain f-electron element, crystallizes in the ZrCuSi2-type tetragonal structure and has shown that the antiferromagnetic (AFM) ordering occurs at 5 K, and anomalies of the temperature dependence of the electrical resistivity and magnetic susceptibility have been observed. It also exhibits a strong magnetic anisotropy, possessing the AFM easy axis along the (001) direction determined experimentally. We investigated the electronic structures of AFM CeAuSb2 by using the full-potential linearized-augmented-plane-wave method to elucidate the correct ground state. By comparing the total energies we will discuss that correct ground state of this compound using spin-polarized calculation and the so-called LDA + U method. A possible scenario will be discussed.

[1] A. Thamizhavel, T. Takeuchi, T. Okubo, M. Yamada, R. Asai, S. Kirita, A. Galatanu, E. Yamamoto, T. Ebihara, Y. Inada, R. Settai, and Y. Onuki, Phys. Rev. B68, 054427 (2003).



P35

Doping effects on the global phase diagram of the heavy-fermion superconductor CeRhIn5

Soonbeom Seo1, SolJu1, E. D. Bauer2, J. D. Thompson2, Tuson Park1

1Department of Physics, Sungkyunkwan University, Suwon 440-746, South Korea2Los Alamos National Laboratory, Los Alamos 87545, USA

E-mail address: [email protected] The prototypical antiferromagnet (AFM) heavy fermion compound CeRhIn5 shows superconductivity by applied external pressure. On the other hand the antiferromagnetic order is suppressed with pressure to reveal an AFM quantum critical point at the optimal pressure of 2.3 GPa [1,2]. When doped with Hg, a hole doping, TN is initially suppressed, becomes flat, and increases with Hg concentration [3]. In this presentation, we report electrical resistivity of the Hg-doped CeRh (In0.9955Hg0.0045)5 and CeRh (In0.99Hg0.01)5, for current applied within and perpendicular to the Ce-In plane under pressure. Even though the antiferromagnetic order is strongly influenced by Hg doping, superconductivity seems almost independent of the Hg doping. These results suggest that the chemical substitution of In by Hg creates a local changesurrounding the Hg dopant, which is similar to the inhomogeneous superconducting phase that was recently observed in the Cd-doped CeCoIn5 [4].

[1] T. Park et al., Nature, 440, 65 (2006).[2] G. Knebel et al., Phys. Rev. B, 74, 020501 (2006).[3] E. D. Bauer et al. , Physica B, 403, 1135 (2008).[4] S. Seo et al., Nature Physics, 10, 120 (2014).



P36

Heat capacity Measurement of the pressure-induced superconductor Sn-doped CeRhIn5

Sungil Kima, Soonbeom Seoa, D. Shina, Tuson Parka

aSungkyunkwan University, Suwon, Korea


Unconventional superconductivity is often found as a magnetic transition is tuned towards a magnetic quantum critical point (QCP), where the magnetic ordering temperature is completely suppressed to zero Kelvin. The heavy fermion compound CeRhIn5 has been shown to be fruitful to study the relationship between QCP and unconventional superconductivity because the highest superconducting transition temperature occurs at the QCP. When doped with Sn, hybridization strength between localized Ce 4f and itinerant electrons is shown to increase, therefore resulting in the suppression of the AFM ordering temperature in Sn-CeRhIn5. The suppression in TN suggests that AFM QCP may be shifted to lower pressure. Here we report heat capacity and electrical resistivity of Sn-doped CeRhIn5 under pressure. Evolution of the magnetic phase as well as the superconducting phase will be discussed.

Keyword : Quantum critical point, quantum fluctuation, unconventional superconductivity

[1] S. Seo, "Disorder in quantum critical superconductors", Nature physics 10, 120-125 (2014).



P37

Effects of La doping in the antiferromagnet CeIn3

Suyoung Kim, In Cheol Kim, T. Klimczuk, Tuson Park

Department of Physics, Sungkyunkwan University, Suwon 440-746, KoreaDepartment of Physics, Gdansk University, Gdansk, Poland

E-mail address: [email protected] Ce-based heavy fermion compounds have attracted great interest due to the interplay between magnetism and superconductivity. CeIn3 is an antiferromagnet below 10 K at ambient pressure and becomes superconducting under pressure. At the critical pressure of 2.5 GPa, where Tc is maximum, temperature dependence of the resistivity has been shown to deviate from Landau-Fermi T2 dependence, indicating that critical fluctuations associated with the suppression of the antiferromagnetic state may be relevant to superconductivity. Here we present effects of La-doping to CeIn3. We measured resistivity and heat capacity for several La doping concentrations. Phase diagram will be presented as a function of temperature. Non-Fermi liquid behavior will be also discussed in connection with quantum magnetic phase transition that is hidden inside the superconducting dome.

Key word: CeIn3, AC calorimetry, Neel temperature, superconductivity

[1] D. Gout et al., “An Experimental and Theoretical Study of the Variation of 4f Hybridization Across the La1-x CexIn3 Series” Inorg. Chem, 2008, 47(7), 2569-2575



P38

Field Emissions of Single Crystalline -Naβ 0.33V2O5

Nanowires

Nguyen Thi Hong Trang, Shakir Imran, Muhammad Shahidand Dae Joon Kang


High quality single crystalline sodium vanadate ( -Naβ 0.33V2O5) nanowires were grown directly on conducting silicon substrates by a facile chemical solution deposition method without employing catalyst, surfactant or carrier gas. X-ray diffraction, high resolution field emission microscopy and transmission electron microscopy analysis indicate that b-Na0.33V2O5 nanowires were grown along [001] direction and have an average diameter of about 120 nm and length over 10 µm. The growth mechanism for -Naβ 0.33V2O5 nanowires were also proposed in detail. The electrical transport measurement employing a four terminal configuration shows that the conductivity of -Naβ 0.33V2O5 nanowires measured along the growth direction was found to be about 0.57 S/cm, in good agreement with literature elsewhere. The field emission characteristics of -Naβ 0.33V2O5 nanowires were also investigated. It was found that high current density (550 mA/cm2) and low turn-on field voltage (0.6 V/mm) as well as high stability were obtained. The results suggest that -Naβ 0.33V2O5 nanowires can be used as a promising material for novel electronic devices and field emission devices.



P39Large scale Synthesis of Large Area Transition Metal

Dichalcogenide Atomic Layer by a Simple Sulfurization

Jaeseok Hwang and Dae Joon Kang



Many researchers have tried to explore the unique electrical and optical properties of transition metal dichalcogenides (TMDs). Especially, molybdenum disulfide (MoS2) has attracted a great attention as it is considered to be a promising alternative to replace graphene for many viable electronic applications. We designed a novel growth method for obtaining high quality MoS2 atomic layers based on thermodynamics and simple sulfurization method. We uniformly synthesized a few-layer of ultra-large area MoS2 thin films a up to 2 inch by a sulfurization route. We showed that the number of layer can be easily tuned by controlling the growth temperature and the growth time. Moreover, we developed a facile transfer technique for the transfer of as synthesized MoS2 layers to other substrates including SiO2/Si substrates. We investigated their structural and optical properties by using photoluminescence and Raman spectroscopy. Our results suggested that a simple sulfurization process can be exploited to obtain a few-layer of ultra-large area TDMs thin films. This may open up a great opportunity for the exploration of novel TMDs to many viable applications.



P40Sub-100nm Pattern Replication Via

Electrohydrodynamic Lithography Exploiting AC Voltage with Resonating Frequency

Choongman Moon and Dae Joon Kang



Electrohydrodynamic lithography (EHL) is a non-conventional pattern transfer technique which makes use of the behavior of liquid film under strong electric field, placed between two electrodes to form laterally ordered structures. The size of laterally ordered structure generated by EHL has a tendency to be similar with the characteristic wavelength, so there have been many studies to reduce the characteristic wavelength. Here, simple method is suggested to shorten the characteristic wavelength by using RLC circuit. We added an inductor in series with a capacitor-like structure and applied alternating voltage with resonating frequency. It could apply high voltage over capacitor-like structure that the characteristic wavelength could be decreased to sub-micron scale. According to the previous works, the smallest feature size attainable was around 10% of the characteristic wavelength that we expect sub-100nm scale patterning technique to be much cheaper and easier than the conventional lithography.



P41

Improved critical current density of FeSe by pressure-induced magnetism

Soon-Gil Jung1, Ji-Hoon Kang1, Eunsung Park1, Sangyun Lee1, Jiunn-Yuan Lin2, Dmitriy A. Chareev3, Alexander N. Vasiliev4,5,6, and

Tuson Park1,*

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Republic of Korea2Institute of Physics, National Chiao Tung University, Hsinchu 30010, Taiwan

3Institute of Experimental Mineralogy, Chernogolovka, Moscow Region, 142432, Russia4Low Temperature Physics and Superconductivity Department, Physics Faculty, Moscow State University,

119991 Moscow, Russia5Theoretical Physics and Applied Mathematics Department, Institute of Physics and Technology, Ural

Federal University, Ekaterinburg 620002, Russia6National University of Science and Technology "MISiS", Moscow 119049, Russia

E-mail address: [email protected] Iron selenide (FeSe) superconductor has recently drawn a significant interest due to greatly controllable superconducting transition temperature (Tc). The pressure-induced high Tc of 37 K in bulk FeSe and Tc of 65 K in FeSe monolayer also present its possibility for technological applications [1,2]. Critical current density (Jc) is the most important parameter for technological applications of superconductor, and therefore an investigation into the relation of Jc and Tc is essential. Here, we have investigated the Jc behaviour for FeSe single crystals under pressure up to 2.43 GPa. The Jf determined at free flux flow region monotonically increases with raising Tc, whereas the Jc obtained from the criterion of 1 V, corresponding to the depinning Jμ c, is not concomitant with enhanced Tc as much as the Jf. Interestingly, the Jc is suddenly enhanced at 1.22 GPa at which antiferromagnetic ordering emerges. In addition, below 1.22 GPa the spatial variation of Tc ( Tδ c-pinning) plays a main role for the Jc, while at higher pressures the spatial variation of charge carrier mean free path (l) fluctuations (δl-pinning) becomes important for the Jc accompanied with spin fluctuations or magnetic order. In this study, we will discuss that the origin of the anomalous enhancement in Jc is closely tied to the pressure-induced antiferromagnetism.

[1] Medvedev, S. et al. Electronic and magnetic phase diagram of -Feβ 1.01Se with superconductivity at 36.7 K under pressure. Nature Mater. 8, 630-633, (2009). [2] He, S. et al. Phase diagram and electronic indication of high-temperature superconductivity at 65 K in single-layer FeSe films. Nature Mater. 12, 605-610 (2013).



P42

Effects of thermal annealing in the Iron-based Superconductor Ba(Fe1-xCox)2As2 under pressure

D. Shin1, G. Prathiba1, S. Seo1, K. Choi2, K. Kim2, T. Park1

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea2Department of Physics and Astronomy, Seoul National University, Seoul 151-747,

Korea


Superconductivity in the Fe-based compound BaFe2As2 (Ba122) can be induced by either externally applied pressure or chemical (electron/hole) doping [1]. Recently it is reported that thermal annealing can significantly enhance not only the superconducting transition temperature (Tc) but also spin density waves (SDW; TN) and other physical properties in underdoped Ba(Fe1-xCox)2As2 (Co-Ba122) compound [2]. However, the origin of thermal annealing effects has yet to be clarified. In order to investigate the effect of annealing, we have measured electrical resistivity of unannealed and annealed underdoped Co-Ba122 single crystals under external pressure and constructed temperature-pressure phase diagram. Several plausible scenarios of the thermal annealing effects will be comparatively discussed.

Keywords : Co-Ba122, Thermal annealing, Electrical resistivity, Pressure, Superconductivity, Spin Density Waves (SDW), The non-Fermi liquid behavior

[1] Y. Kamihara, T. Watanabe, M. Hirano, and H. Hosono, J. Am. Chem. Soc. 130, 3296, (2008).[2] K. Gofryk, A. S. Sefat, M. A. McGuire, B. C. Sales, D. Mandrus, T. Imai, J. D. Thompson, E. D. Bauer, F. Ronning, Phys. Rev. B 83, 064513 (2011).



P43

Synthesis and study of BaFe2Se3 compounds with low volume fraction superconductivity at Tc = 13 K

H. Jang, S. Shin, Soon-Gil Jung, T. Park*

Department of Physics in Sungkyunkwan University, Suwon, Korea


BaFe2Se3 polycrystals were synthesized by multistep processes using FeSe polycrystal or multiphase Fe2Se3 precursor. And the needle-shape single crystals of BaFe222Se3 were fabricated via a Te flux method. XRD (X-ray diffraction) analysis of BaFe2Se3 compounds indicates double chains of edge shared Fe-Se tetrahedral structure (Pnma Space group) which propagates to b-axis. And compounds using FeSe precursor and multiphase Fe2Se3 show very similar XRD results. MPMS (magnetic property measurement system) data suggests a low volume fraction of superconductivity in the BaFe2Se3 single crystals with a Tc of ~ 13 K.

[1] V. Svitlyk et al., J. Phys.: Condens. Matter 25 315403 (2013)[2] A. Krzton-Maziopa et al. , J. Phys.: Condens. Matter 24, 059502 (2012)[3] Hechang Lei et al., Phys. Rev. B 84, 214511 (2011).



P44Electronic structures and optical properties of XN

(X=Al, Ga, B, In) compounds: Improved density functional theory calculations

M. M. Alsardia,1,2 Joo Yull Rhee,1 M. A. Saeed2

1Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea2Physics Department, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia


In the present work, we investigate the electronic and optical properties of XN (X=Al, Ga, B, In) compounds with the recently developed modified Becke-Johnson potential plus generalized gradient approximation (TB-mBJ) within density functional theory. The current comparative calculations show that the band gaps have been improved significantly by the TB-mBJ compared to the generalized gradient approximation (GGA-PBE) and local-density approximation (LDA) and are in good agreement to the experimental values. From the band structure, it is clearly seen that N-p states dominate the valence band. The optical properties of these binary compounds are very important; therefore, different optical parameters (complex dielectric function, refractive index, extinction coefficient, optical reflectivity, optical conductivity, absorption efficient and electron energy loss), are also calculated. All peaks in all these parameters shift towards higher energies with TB-mBJ. The values of the static dielectric constant ε1(0), static refractive index n(0) and reflectivity R(0) by LDA/GGA are in agreement to the experimental values.



P45Analysis of incident-angle dependence of absorption spectrum of simple metamaterial absorber near 3rd

harmonic resonance frequency

Changhyun Yi, Joo Yull Rhee

Department of Physics, SungKyunKwan University, Suwon, 440746, Korea


Metamaterial (MM) is a periodic array of subwavelength units, possessing special characteristics which does not exist in nature. Metallic cut wire (CW) is widely used unit, and there are many studies based on this structure but most of them utilize only the fundamental mode where the metal bars show current distribution like dipole antennas. Recently, it was reported that a strong resonance is observed when the frequency is about three times higher than the fundamental mode. There were some trials utilizing this mode as a MM-base perfect absorber, but there was an unexpected minor peak just above the third-harmonic peak. Even more, complex incident-angle dependence was observed. In this study, we elucidate the physical origin of the spectrum and its incident-angle dependence. We found that the Wood's Anomaly plays an important role to determine incident-angle dependence of both the third-harmonic and the minor peaks.



P46

Studies on Metamaterial-based Broadband Perfect Absorbers

Hoang Trong Linh1, Joo Yull Rhee1

1Department of Physics, Sungkyunkwan University,Suwon, Kyunggi-do 440-746, South Korea


Metamaterials are assemblies of multiple individual elements which are designed and fabricated to possess a lot of properties which are not observed in natural materials. One of interesting properties is to lead perfect absorption in both narrow and broad bands of frequency range. Metamaterial-based absorbers usually consist of three layers. The topping is periodically-arranged patterns which are made of metal and high-impedance surface. The middle layer is a dielectric layer which may have high permittivity or high loss tangent. And the bottom is an infinite metal layer which blocks all incident electromagnetic wave. In this work, designs and fabrications are discussed to perform perfect absorption in both narrow and wide bands in low Gigahertz range.



P47

Crystal Structure of -BiFeOα 3: a First-Principles investigation

Fayyaz Ahmad,1 Ishrat Naz,1 Joo Yull Rhee1

1Department of Physics, Sungkyunkwan University, Suwon, 440746, Korea


Density-functional-theory-based calculations have been carried out to investigate the crystal structure of bismuth ferrite ( -BiFeOα 3). A generalized-gradient approximation has been employed for the exchange-correlation functional. In experiment [1] several different crystal structures were suggested, and it was claimed that the triclinic phase (space group: P1) is the most suitable one. In order to check this claim we carried out the total-energy calculations for different crystal structures. Indeed, we found that the triclinic phase had the lowest total energy. Furthermore, only the triclinic phase has the direct band gap of 0.78 eV. To understand the differences among different models, we investigated the density of state, band structure and charge/spin density. The direct band gap corresponds to the energy separation between the top of the O 2p valence band and bottom of the Fe 3d conduction band

[1] H. Wang et al., Inorg. Chem. 52, 2388 2392 (2013)−

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