High Tc Superconducting Applications in Geophysical Exploration and Telecommunications

MANUFACTURING and DATA61

C.P. Foley

CSIRO Team: Jia Du, Keith Leslie, Emma Mitchell, Shane Keenan, Kirsty Hannam, Jeina Lazar, Chris Lewis, Bill Vasilevski, Karl Wilson, Andrew Weily, Xiang Gao, Ting Zhang, Wendy Purches, Alex Gracea, Kyle Blay

Relationship of Geophysical Exploration

and Communications

USA Population: 0.3B

Australian Population: 0.02B

Australia has the same

population as Shanghai

Presentation title | Presenter name | Page 4

Communication across vast distances to small populations

5 |

This talk

• Josephson junctions in HTS – recent emergence of step edges

• Geophysical applications• Magnetometers

• Gradiometers

• High frequency devices

• New concept antennas

7 |

YBCO is not an easy material

Nature Materials 6, 631 - 642 (2007) S. R. Foltyn, L. Civale, J. L. MacManus-Driscoll, Q. X. Jia, B. Maiorov, H. Wang & M. Maley

• Highly anisotropic

• a-b coherence length ≈ 2 nm

• One element is a gas

1 µm

1 µm

| Dimos et al Phys Rev B 1990 41 4038

1 nm

Making a Josephson junction in HTS

Enpuku and Minotani Simplistic Model IEICE Trans Electron E83-C (2000) 34

SuperconductorSuperconductor Insulator

Cooper Pair Direct tunnel (d-wave symmetry)

Direct tunnel

Resonant tunnel

Trap and escape (1/f noise)

Quasiparticles

| Fagaly Review of Scientific Instruments (2006) 77 101101

Bicrystal and ion beam damaged

Step edgeRamp

Important parameters:

- IcRn – aim for 1000 µV

- Critical current fluctuations with B

- Ic control <9% spread

Bicrystal Junctions

IcRn product of symmetric 20o bicrystal junctions ∼400 μV at 77.4 K

Ramp Junctions

|

Moeckly and Char APL 1997 71 2526

Wen et al Applied Physics Letters 75, 2470 (1999)

IcRn at 77 K 156 µV

Step edge grain boundary junctions

|

STO

MgO

c axis

c axis

Why MgO?

LAO

“Step-edge Josephson junctions and SQUIDs” F. Lombardi and A. Ya. Tzalenchuk

Step Edges on MgOJulich Group

M. Faley et al IEEE Transactions on Applied Superconductivity 23(3):1600705-1600705

CSIRO Group

30 papers eg C. P. Foley et al., IEEE Trans. Appl. Supercond. 9 (1999) 4281E.E. Mitchell and C.P. Foley, SUST. 23 (2010) 065007

S.Tanaka et al IEEE Trans. Appl. Supercond. 3 (1993) 2365

Sumitomo Electric National Taiwan University

C.H. Wu et al Physica C 433 (2005) 108

Soon Jena

Can you do over the edge but not come back up?

“Escher steps”

Development of a step edge Josephson junction

24 |

First efforts

Presentation title | Presenter name | Page 26

CSIRO HTS Step-edge Josephson Junction technology - many HTS electronic devices built upon

1m

Θ= 36.8±0.2o

YBCO film

C. P. Foley et al, IEEE Trans. Appl. Supercond. 9 1(999) 4281.E.E. Mitchell and C.P. Foley, Supercond. Sci. Technol. 23 (2010) 065007

Junction noise in a magnetic shield

0

1

2

3

0.4 0.6 0.8 1.0

cath1.ep

BC2 bi-xtal

ML384Pk.1Pk.2

ML789Pk.2 Pk.1

ML635

T/Tc

Sv (

nV

Hz

-1/2

)VOLTAGE NOISE vs. REDUCED TEMPERATURE FOR

3 STEP-EDGE JUNCTIONS (ML***) AND 1 BI-XTAL JUNCTION

0

0.5x10-6

1.0x10-6

1.5x10-6

0 0.4 0.8 1.2

(d) bc2b(d)

(c)

(c) ml635T70K

Step-edge Junctions ml789 A, ml635and Bi-crystal junction bc2b

c7&icib1.ep

(a) ml789, 1st Peak(b) ml789, 2nd Peak

(b)

(a)

B (mT)

Ic(B

) /I c(0

) (H

z-1/2

)

CRITICAL CURRENT FLUCTUATIONS vs. MAGNETIC FIELD

Critical Current fluctuations in applied magnetic fields

Bicrystal

Step edge

Lindfield Clean Room – HTS FoundaryDesign rules available

Geophysical ExplorationApplicationsMagnetometer – Active TEM

RF SQUID - 1 junction

|

X

conductorDecaying eddy current

Transient Electromagnetics (TEM)

1992-1993

First HTS Ground-based TEM system

BHPB

1994-1997

“Airborne System”

BHPB1999-2001

Prototype unit

Falconbridge/Crone2002-2004

LANDTEMTM

Outer-Rim Exploration Services

RF SQUID LANDTEMTM system

35 |

2 Junction: HTS DC SQUIDs

Field noise ~ 30 fT/root Hz (white)

Flux noise ~ 5 /root Hz

HTS Gradiometers

37 / 20

Gradiometers Systems using High Tc Junctions

Rotating axial gradiometersSensitivity – 10 pT/m/Hz at 10 Hz unshielded need 3

Static planar gradiometers (hexagonal-prism)Sensitivity – 2 pT/m/Hz at 10 Hz unshielded need 6

Rotating planar gradiometer-initial results; continuing improvement – need 1!Sensitivity ~ 50 pT /(m.√Hz) in rotation at 2nd harmonic (30 Hz) Stable operation in Earth’s field

1. 2. 3.

z

yx

Rotating the Axial Gradiometer.

• Fourier transform of signals from three rotating gradiometers provides information to derive all the components of the magnetic field gradient tensor and magnetic field vectors, providing information about the bearing and range to the target

• Common Mode Rejection of Earth’s field achieved by frequency separation.

- Gradient terms at 2x rotation frequency

- B field components at rotation frequency.

• Rotating system raises the vibration isolation requirements above ~15 Hz; advantageous for most airborne platforms

Rotating axial gradiometer

Fourier transform of the 2nd harmonic time series.Additional noise reduction using least squares fitting

Gradient noise density of a single rotating axialgradiometer

• Gradient signal modulated to second harmonic 2.

• Common mode response modulated to first 1

• Sensitivity – 10 pT/m/Hz at 10 Hz unshielded operation

1

2

Helicopter trial over a magnetic target

Slide Presentation Title

Two Drum System: Comparison of calculated and actual measured components

P-Drum Simulated

-100

-50

0

50

100

150

-15 -10 -5 0 5 10 15

distance (m)

gra

d (

nT

/m)

gxy

(gxx-gyy)

P-Drum Simulated

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

-15 -10 -5 0 5 10 15

distance (m)

gra

d (

nT

/m)

gxy

(gxx-gyy)

0 100 200 300 400 500-150

-100

-50

0

50

100

1500 5 10 15 20 25 30

Gra

die

nt

(nT

/m)

FFT number

P Components

6 A-m, 2 m CPA

Bxx

minus Byy

Bxy

0 100 200 300 400 500-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.00 5 10 15 20 25 30

Gra

die

nt

(nT

/m)

FFT number

P Components

6 A-m, 2 m CPA

Bxx

minus Byy

Bxy

Measurement setup hexagonal system

Static planar tensor gradiometer

Presentation title | Presenter name44 |

• Six planar flip chip gradiometers

• 3 reference SQUID magnetometers

• Sensitivity – 2 pT/m/Hz at 10 Hz unshielded operation

Extracted tensor components from a 6 A.m2

dipole magnet pass

Gradient noise density of a single planar gradiometer

Calculated scaled moment vs the theoreticalmoment for a dipole magnet pass

Rotating Planar GradiometerR-Tensor –early development

R-Tensor is a magnetic tensor gradiometer that requires only a single rotating planar SQUID gradiometer to measure all the independent components of the magnetic gradient tensor.

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• reduces system complexity (one sensor verses typically five minimum)

• significantly reduces size, weight and power (SWaP) requirements

• single rotating planar SQUID gradiometer + orthogonal referencing for field compensation (improves accuracy of some components)

• current sensitivity ~ 50 pT /(m.√Hz) @ 30 Hz (rotational rate)

• currently ~4 hours of continuous operation

Concept • 2nd Harmonic – free from common-mode

• 1st harmonic + DC contaminated with common-mode, reduced with field referencing

• Response to a moving dipole 2.8 A.m2 – CPA = 1.2 m (8 m track)

zzzyzx

yzyyyx

xzxyxx

BBB

BBB

BBB

G

f 2f

Frequency

DC

1st Harmonic2nd

Harmonic

Tensor

components

contained within

the in-phase and

quadrature of the

harmonic

HTS Devices for Communication

47 |

Josephson Junctions for High Frequency Applications

• AC Josephson Effect: ƒ (2e/h)Vo, 2e/h = 0.4836 GHz/V

V0 from V to mV, f falls into the microwave, mm, sub-mm/THz bands

Generate rf signal of variable frequency controlled by a voltage

Detect an incoming rf signal

Measure and detect voltage with extremely high precision

• Advantages of SC active devices:

extremely low noise

low power consumption (nWs)

high freq and wide band operation

(due to high-energy gap)

-2.5

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5-2 -1 0 1 2

-1T -500G 0 500G 1T

0

10

20

30

V (mV)

no CB

1 CB

2 CB

3 CB

THz blocked

I (m

A)

spectrum

Hilb

ert

Spectr

um

(a.u

.)

Frequency (Hz)

HTS microwave passive devices developed – Low loss, high selectivity, high Q-factor

10 mm

T. Zhang, J. Du, et al. Electronics Letters, 48, (2012).

T. Zhang, J. Du, et al. Supercond. Sci. Technol. 25

(2012) 105014

T. Zhang, J. Du, et al., Physica C, 495, 69-73, 2013.

D. Bai, J. Du, et al., JAP, 114 (2013) 133906.

HTS Josephson Junction microwave active devices – some examples developed

YBCO step-edge junctions

Au film resistor

500.0M 1.0G 1.5G 2.0G 2.5G

0.0

0.2

0.4

0.6

0.8

1.0

No

rma

lise

d V

2

Freq. (Hz)

JD318F in cryocooler at 55K, IB = 390 uA, vary Ir, 2/4/09

• HTS Josephson Junction is a highly nonlinear active device.

Tuneable heterodyne GHz oscillatorSelf-pumped tuneable JJ mixer

Refs:

•J. Du and J. C. Macfarlane, Electronics Letters, 47 (2011) 772.

•J. Du, et al, Supercond. Sci. Technol. 25 (2012) 025019.

•J. Du, et al., J. Appl. Phys. 111, 053910 (2012).

• D. Bai, J. Du and Y. S. He, IEEE Trans Appl. Supercond., vol. 24 (5), 1501404, 2014.

IF

LO

RF

An advanced receiver based on HTS technology

Can enhance sensitivity & selectivity

Can achieve high-speed broadband communication

Integrate HTS passive and active components onto single chip,

i.e. MMIC (microwave monolithic integrated circuit) Josephson

junction mixer

Develop a low-noise receiver front-end

High-Tc Superconducting (HTS) Monolithic Microwave Integrated Circuit (MMIC) RF Receivers

• Stable operation between 20 to 80 K.

• Conversion gain ~-1±0.5dB at 20 K (~ 0 dB

deducted the filter Ils). The highest value

demonstrated for HTS mixers.

• On-chip Integration:

o Improve coupling efficiency

o Isolation of input and output circuits

o Remove losses due to connections

o Compactness

o Lower power consumption

High-Tc Superconducting Receiver Technology for Ka band (26.5–40 GHz) high-speed, long-range communications

Enabling:

• Inter-satellite communications

• Communications between ships and satellite, …

Demonstrated :

• a compact (2.5 x 2 x1.5

cm3),

• high-gain (40 dB) and

• low noise (~ 0.1 dB)

• Ka band HTS receiver

front-end module.

Smart Devices/Systems for Future Terahertz Communications

• Unprecedented growth in wireless communication push freq. towards millimeter and THz range

• THz – higher carrier freq. and broad bandwidth, potential for ultra high-bit rate wireless communication (tens of gigabit to terabit/s data rate).

• Problems:

• (1) High atmospheric attenuation –ultra-sensitive heterodyne mixers required

• (2) Lack components/systems (beyond microwave tech and below optical tech)

• Research Aim: develop heterodyne mixers for THz sensing and communication applications

A Ring-slot antenna - coupled HTS Step-edge JJ Harmonic Mixer – cooled on a PT cryocooler

J. Du, et al , Supercond. Sci. Technol. 29, in print, 2016

Mixing with 20th

harmonic of LO

frequency to

down-converted

from 600 GHz to

2.4 GHz

Intermediate

frequency (IF)

Broadband THz Mixer:

Principal Investigator: Dr Xiang Gao

Harmonic Mixing CharacterizationFrequency response characterization – broadband (over 24 GHz

bandwidth)

200-GHz band 600-GHz band

The black traces refer to directly measured results. The red traces refer to processed results

after calibration of the whole IF link and frequency-dependent THz source power.

To be published

RF Measurement

58 |

Temperature dependence:

Operating at T up to 77K !!

IF Output vs the harmonic number

Broadband Response: SQUID voltage power spectrum –no rf

fc

2fc

dc

Broadband response: SQUID voltage power spectrum – rfat 12GHz

fc

2fc

fRF

dc

|

SQIFs

|

Design #1 100,200 Junctions βL = 0.4

Design #2 20,000 Junctions βL = 0.4

Design #3 20,000 Junctions βL < 1

23360 V/T

5740 V/T

1530 V/T

Increasing HTS SQIF array size & sensitivity

63 |

• N= 100,200

• Substrate = 1cm2 MgO

• Scaling up to 4cm2

MgO with N= 1,000,000

Broadband RF response of HTS SQIF array

• N = 100,200

• VB = 23.3 kV/T

• Flat band response to 300 MHz

• Recent detection of multiple AM

radio stations (not shown)

Comparison of Cryocooler Alignment

65 |

Summary

• HTS step edge Josephson Junctions on MgO make good devices

• HTS gradiometers – new concept is promising with a single planar gradiometer rotated

• Various telecommunication components in HTS have been demonstrated with excellent performance • Filters are proving successful

• Full monoliths - still to clarify value

• New SQIF antennas demonstrated but still to get the sensitivity to desired levels

66 |

67 |

Real

x xImaginary

Planned

IWSSD 2016

IWSSD 2018

Thank you!

See you in Sydney 2018!