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arXiv · 0901.4242

Mesoscopic conductance fluctuations in InAs nanowire-based SNS junctions

T. S. Jespersen·M. L. Polianski·C. B. Soerensen·K. Flensberg·J. Nygaard
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Abstract

We report a systematic experimental study of mesoscopic conductance fluctuations in superconductor/normal/superconductor (SNS) devices Nb/InAs-nanowire/Nb. These fluctuations far exceed their value in the normal state and strongly depend on temperature even in the low-temperature regime. This dependence is attributed to high sensitivity of perfectly conducting channels to dephasing and the SNS fluctuations thus provide a sensitive probe of dephasing in a regime where normal transport fails to detect it. Further, the conductance fluctuations are strongly non-linear in bias voltage and reveal sub-gap structure. The experimental findings are qualitatively explained in terms of multiple Andreev reflections in chaotic quantum dots with imperfect contacts.

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T. S. Jespersen, M. L. Polianski, C. B. Soerensen, K. Flensberg, J. Nygaard. 2009-05-26. Mesoscopic conductance fluctuations in InAs nanowire-based SNS junctions. https://doi.org/10.1088/1367-2630%2F11%2F11%2F113025

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