Numerical Study on Josephson-Current Fluctuations in a Dirty SNS Junction: The Effect of Incomplete Andreev Reflection

1996 ◽  
Vol 65 (3) ◽  
pp. 683-686 ◽  
Author(s):  
Yasusi Koyama ◽  
Yositake Takane ◽  
Hiromichi Ebisawa
Keyword(s):  
Andreev Reflection ◽  
Numerical Study ◽  
Josephson Current ◽  
Current Fluctuations ◽  
Sns Junction

Mesoscopic Fluctuations of the DC Josephson Current in a Dirty SNS Junction

1997 ◽  
Vol 66 (10) ◽  
pp. 3314-3314
Author(s):  
Yasusi Koyama ◽  
Yositake Takane ◽  
Hiromichi Ebisawa
Keyword(s):  
Josephson Current ◽  
Sns Junction

scholarly journals Proximity effects and Andreev reflection in a mesoscopic SNS junction with perfect NS interfaces

2000 ◽  
Vol 61 (17) ◽  
pp. 11340-11343 ◽  
Author(s):  
Z. D. Kvon ◽  
T. I. Baturina ◽  
R. A. Donaton ◽  
M. R. Baklanov ◽  
K. Maex ◽  
...  
Keyword(s):  
Andreev Reflection ◽  
Proximity Effects ◽  
Sns Junction

scholarly journals Nonlocal supercurrent of quartets in a three-terminal Josephson junction

2018 ◽  
Vol 115 (27) ◽  
pp. 6991-6994 ◽  
Author(s):  
Yonatan Cohen ◽  
Yuval Ronen ◽  
Jung-Hyun Kang ◽  
Moty Heiblum ◽  
Denis Feinberg ◽  
...  
Keyword(s):  
Josephson Junction ◽  
Cross Correlation ◽  
Bound State ◽  
Josephson Current ◽  
Nonlinear Regime ◽  
Current Fluctuations ◽  
Andreev Bound State ◽  
Microscopic Origin ◽  
Rule Out ◽  
Made In

A novel nonlocal supercurrent, carried by quartets, each consisting of four electrons, is expected to appear in a voltage-biased three-terminal Josephson junction. This supercurrent results from a nonlocal Andreev bound state (ABS), formed among three superconducting terminals. While in a two-terminal Josephson junction the usual ABS, and thus the dc Josephson current, exists only in equilibrium, the ABS, which gives rise to the quartet supercurrent, persists in the nonlinear regime. In this work, we report such resonance in a highly coherent three-terminal Josephson junction made in an InAs nanowire in proximity to an aluminum superconductor. In addition to nonlocal conductance measurements, cross-correlation measurements of current fluctuations provided a distinctive signature of the quartet supercurrent. Multiple device geometries had been tested, allowing us to rule out competing mechanisms and to establish the underlying microscopic origin of this coherent nondissipative current.

Hydrogen-impurity-induced conductance peaks in constriction type Josephson junctions

2021 ◽  
Author(s):  
Kazuki Miyakawa ◽  
Hiroki Takata ◽  
Taishi Yamaguchi ◽  
Yuji Inagaki ◽  
Kazumasa Makise ◽  
...  
Keyword(s):  
Temperature Variation ◽  
Josephson Junctions ◽  
Andreev Reflection ◽  
Josephson Current ◽  
Differential Conductance ◽  
Superconducting Gap ◽  
Impurity Effects ◽  
Hydrogen Impurity ◽  
Multiple Andreev Reflection

Abstract We studied hydrogen (H) and deuterium (D) impurity effects of superconducting Josephson current flowing through the superconductor-constriction-superconductor Josephson junctions (ScS-JJ). When H or D impurities are adsorbed on the surface of the ScS-JJ prepared by niobium (Nb) or lead (Pb), many spike-like peaks with almost the same spacing appear inside the superconducting gap in addition to anomalies owing to the multiple Andreev reflection in the differential conductance spectra. The spacing between the adjacent peaks is independent of the temperature variation. These indicate that H or D impurities adsorbed on the JJ are sources of noise for the Josephson current.

scholarly journals NUMERICAL STUDY OF π-JUNCTION USING SPIN FILTERING BARRIERS

2009 ◽  
Vol 23 (20n21) ◽  
pp. 4320-4328 ◽  
Author(s):  
SHIRO KAWABATA ◽  
YASUHIRO ASANO
Keyword(s):  
Quantum Information ◽  
Band Structure ◽  
Josephson Junctions ◽  
Function Method ◽  
Numerical Study ◽  
Josephson Current ◽  
The Other ◽  
Other Hand ◽  
Spin Polarized ◽  
The Eu

We numerically investigate the Josephson transport through ferromagnetic insulators (FIs) by taking into account its band structure. By use of the recursive Green's function method, we found the formation of the π junction in the case of the fully spin-polarized FI (FPFI), e.g., La 2 BaCuO 5. Moreover, the 0-π transition is induced by increasing the thickness of FPFI. On the other hand, Josephson current through the Eu chalcogenides shows the π junction behavior in the case of the strong d-f hybridization between the conduction d and the localized f electrons of Eu . Such FI-based Josephson junctions may becomes a element in the architecture of future quantum information devices.

Mesoscopic Fluctuations of the DC Josephson Current in a Dirty SNS Junction

1997 ◽  
Vol 66 (2) ◽  
pp. 430-441 ◽  
Author(s):  
Yasusi Koyama ◽  
Yositake Takane ◽  
Hiromichi Ebisawa
Keyword(s):  
Josephson Current ◽  
Sns Junction
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