FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010 Time and Spin Resolved PES Fulvio...
-
Upload
madison-andrews -
Category
Documents
-
view
213 -
download
0
Transcript of FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010 Time and Spin Resolved PES Fulvio...
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Time and Spin Resolved PES
Fulvio ParmigianiDepartment of Physics, University of Trieste
and FERMI@elettra
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
The study of the electron dynamics relays on the ability to time-resolve the ultra-rapid scattering processes which result in energy and momentum relaxation, recombination and diffusion.
In typical experiments a short-pulsed (10-100 fs) laser can be used for photoemission experiments in the time-domain, whereas longer laser pulses (1-5 ps) provided by FT limited coherent sources can be used for photoemission experiments in the frequency (energy) domain with unrecorded resolving power.
Experimental techniques must be brought to bear in which band-structure specificity are combined with time resolution. Angle resolved photoemission is particularly suited for such experiments.
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Kin
eticE
nerg
y
UltrahighVacuum
inc
A few new directions in photoemission measurements
Core-levels I(,)
Photo-e- diff./holog.
Bin
din
gE
nerg
yB
ind
ing
En
ergy
Emission anglek
Valence-levels
yx z
Pump Pulse
Angle
En
ergy
K,s
Up to 10 keV
Space &
Time Resol.
Next gen. detector & Low-T sample goniometer
+ Other spectroscopies:XES, XAS,…
X-ray standing wave
NiO(001)
W(110)
Curtesy C. Fadley, UC Davis & ALSProbe Pulse
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
The 10-18 s Challenge with 0.1-1 keV soft X-ray
Nature Physics, June 2007
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Cluster and nanoparticle spectroscopySpokespersons: F. Stienkemeier, (Univ. of Freiburg-D); T. Moeller (Frei University, Berlin)Co-proponents :K.Fauth (MPI- Stuttgart, D), M. Drabbels (EPFL- CH), M. Schmidt(CNRS –Orsay, Fr), U.Buck (MPI-Goettingen, D)
LDM
Carlo Callegari: LDM coordinatorF. Stienkemeir: End station spoke person
COHERENCE+TUNABILITY+POLARIZATION
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Y. L. Chen, W.S. Lee and ZX. Shen- PNAS 106, 963 (2009)
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
HTSCs
Selective excitations (CT and phonons) to study transient states and photo-induced phase transitions.Superconductors (e-ph interactions, magnetism and superconductivity).Magnetic materials (dynamics of the magnetic excitations).Strong correlations in hard- and soft- condensed matter (charge transfer and phonon assisted excitations).
?
LaBaCuO4
sp-band BCS SC- MgB2
doped-C60
IntercalatedGraphite
e-ph
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
fcc-fcc isostructural transition:1.15% volume collapse
cell-length : 5.1612 4.677 cell-volume : 137.4 102.3 symmetry: F m -3 m
2.Curie Weiss magnetism-Pauli Magnetism (zero moment)
alpha-gamma phase transition in cerium:•Promotional Model ?•Mott transition ?•Kondo Volume Collapse ?
Dynamics of the volume collapse
Light induced shock-wave
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Photoelectron SpectroscopyC1s, O1s and
Pt4f XPS
CO adsorption
Fermi surface of BSCCO measured by ARPES. The experimental data shown as an intensity plot in yellow-red-black scale. Green dashed rectagle represents the Brillouin zone of the CuO2 plane of BSCCO.
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
S.F. Mao and Z.J. S.F. Mao and Z.J. Ding, Hefei (TBP)Ding, Hefei (TBP)
More realistic look at low-energy inelastic
mean free paths--theory
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Team:
INFM-Lab. TASCELETTRA
Univ. Rome III,EPFL LURE
ESRF (ID16)0.3 0.2 0.1 0.0 -0.1 -0.2 -0.3
0
50
100
150
200
250
Exp. Fit
Inte
nsity
(C
ount
s)
Binding Energy (eV)
Au Fermi edgeT = 20Kh = 5933eV E
P= 20 eV, slit 0.4 mm
Eexp = 71 meV
VOLPE project: VOLume PhotoEmission with Synchotron Radiation
Panaccione et al. NIMA (2005)Torelli et al., Rev.Sci. Instr. 76, 023909 (2005)
71 meV @ 5933 eV50 meV analyser
High Resolution /High Flux beamline: ID16 @ ESRF
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Requests for TR-PES-control of the photon density per pulse-control of the rr (from 10 MHz to kHz regime)-control of the polarization-photon energy between 10 eV and ~10 keV
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Verdi V1818 W
OPA DFG
SincroLock
MIRA seed in scatola Mira 900
Pulse picker
5 W
13 W
MIRA HP
Stretcher/compressor
SincroLock
RegA exit: 50 fs pulses5 J per pulseR.R. 250 KHz=800 nm
OPA: < 60 fs1200-2400 nm160 nJ
DFG: 2.5-15 m10 nJ
1-10 MHz25 nJ per pulse
83,28 MHz50 nJ per pulse
Time-Resolved and Angle Resolved Photoelectron Spectroscopy – TR-ARPES and Time-Resolved and Spin Resolved ARPES – TR-SR-ARPES (started 2006)
ObjectivesScope of the project is to design and built an angle resolved and time resolved photoemission system with a spin detector.
10 K Minimum Temperature on the Sample 6 degrees of Freedom motorized sub meV Resolution 40 degrees Angular Acceptance Max Ang Resolution 0.1 degrees Plug and play upgradable for Spin detection
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Spin states dynamicsObjectiveThe goal of this project is to measure the spin resolved band dispersion and spin dynamics in solid by harmonics and high harmonics generated from a 250 kHz Ti:SA amplified source
Time-of-Flight analyser@ high operating frequency (up to 5 MHz)
Electron detector Mott polarimeterCollaboration with 4GLS (E. Seddon and C. Cacho)
Two orthogonal Mott-detectors to measure V and H spin components
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Test of the SR-TR ToF on the Au(111) surface states
TR- and AR-PhotoemissionTime and Spin resolved experiments
Fermi surface mapping
Osterwalder et al. PRB 69 pp.241401R, 2004)
Spin-orbit coupling )(2
12
pVSc
H SO
)3cos(2 2 zSO uSuSc
pH
6cos),(3sin),(),()( 630 zrVzrVzrVrV
uzV
rupp
z
ruu
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Comparison between the 1kHz and 250kHz laser system
1kHz laser systemTotal time = 4hTotal statistic = 4*23400 e-
250 kHz laser systemTotal time = 1’ 20’’Total statistic = 4*22400 e-
Space Charge Effects
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Angular distribution
Total time = 2h (2 min/scan)Teta = +/- 22 degLow angle resolution
E0 = 0.26 eVm* = 0.134k0 = 0.011 Å-1
Vacuum level = 5.49 eV
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
High resolution of the SS energy position
E0 = 260 meVm* = 0.134k0 = 0.011 Å-1
EF
Spin integrated Intensity Energy position of the surface states.
20||*
2
0 2kk
mEE
Determination of the SS kinetic energy position with very high precision (±2meV).
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Future Light Sources 1
ANL-08/39BNL-81895-2008LBNL-1090E-2009SLAC-R-917Science and Technology of Future Light Sources
HR-PES
TR-PES
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Future Light Sources 2
ANL-08/39BNL-81895-2008LBNL-1090E-2009SLAC-R-917Science and Technology of FutureLight Sources
Monochrom.
High spatial resolution PES
FLS 2010 ICFA Beam Dynamics Workshop SLAC March 1-5, 2010
Conclusions• TR and SR PE-spectroscopy:1. Control of the photon density in the probing pulse2. Selective pumping excitation3. Controlled repetition rate (from kHz uo to MHz)4. Photon energy range from few eV up to few keV5. Very low temperature sample holder ( 6-degrees freedom)
• Potential results:1. Dynamics of the Fermi surfaces2. Electron-boson and electron-electron interactions in
condensed matter (CDW, SDW and SC transition)3. Electronic and magnetic structure of LDM4. Dynamics of the VB and core elctrons