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Volume 6
Research & Reviews: Journal of Material Sciences
ISSN: 2321-6212
Materials Physics 2018
August 16-17, 2018
August 16-17, 2018 | London, UK
4
th
International Conference on
Condensed Matter and Materials Physics
Nonlocal supercurrent in mesocopic multiterminal SNS Josephson junction
Golikova T E, Lvov D S, Egorov S V, Bobkova I V, Bobkov A M, Batov I E
and
Ryazanov V V
Institute of Solid State Physics - RAS, Russia
A
nonlocal supercurrent was observed in mesoscopic planar SNS Josephson junctions (Al-Cu-Al) with additional
normal metal electrodes (Cu). Nonequilibrium quasiparticles were injected from a normal-metal electrode into the left
superconducting bank of the Josephson junction in the absence of a net transport current through the junction. The value
of nonlocal supercurrent slightly exceeds the local value I
c
and depends on the distance between Josephson junction and the
injector. The detected voltage in the resistive state in nonlocal configuration has opposite sign. We claim that the observed
effect is due to a supercurrent counterflow, appearing to compensate for the quasiparticle flow in the SNS weak link. We have
measured the responses of SNS junctions for different distances between the quasiparticle injector and the SNS junction at
temperatures far below the superconducting transition temperature. Such a choice of the distance scale between injectors and
Josephson junction allows us to exclude coherent CAR and EC effects. The charge-imbalance relaxation length was estimated
by using a modified Kadin, Smith, and Skocpol scheme in the case of a planar geometry. The model developed allows us to
describe the interplay of charge imbalance and Josephson effects in the nanoscale proximity system in detail at low temperatures
(far below the superconducting transition temperature T
c
).
Figure 1. a)
SEM image of an Al-Cu-Al multiterminal Josephson junction with two Cu injectors together with the measurement scheme (solid line - local, dashed
line - nonlocal).
b)
Current-voltage characteristics of an Al-Cu-Al Josephson junction at 0.4 K .
1)
– local measurement;
2)
and
3)
– nonlocal measurements from
the nearest and farest injectors correspondingly.
Recent Publications:
1. D Beckmann, H B Weber, and H V Löneysen (2004) Evidence for crossed Andreev reflection in superconductor
ferromagnet hybrid structures. Phys. Rev. Lett. 93:197003
2. P Cadden Zimansky and V Chandrasekhar (2006) Non local correlations in normal metal superconducting systems.
Phys. Rev. Lett. 97:237003.
3. A M Kadin, L N Smith, and W J Skocpol (1980) Charge imbalance waves and non equilibrium dynamics near a
superconducting phase slip center. J. Low Temp. Phys. 38(3-4):497-534.
4. V K Kaplunenko, V V Ryazanov and V V Shmidt (1985) Effect of non equilibrium quasiparticle flow of SNS Josephson
junctions. Journal of Experimental and Theoretical Physics. 89:1389-1403.
Biography
Golikova T E obtained her PhD Degree in Physics in 2014 and she is working on experimental investigation of the interplay of superconductivity and magnetism
at low temperatures involving structure fabrication with the nanotechnology tools. Her research interest include: superconductivity and magnetism, spintronics,
Josephson junctions.
golt2@list.ruGolikova T E et al., Res. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C2-017