Charge-neutral nonlocal response in superconductor-InAs nanowire hybrid devices

A. O. Denisov, A. Bubis, S. U. Piatrusha, N. A. Titova, A. G. Nasibulin, J. Becker, J. Treu, D. Ruhstorfer, G. Koblmueller, E. S. Tikhonov, V. S. Khrapai*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Nonlocal quasiparticle transport in normal-superconductor-normal (NSN) hybrid structures probes sub-gap states in the proximity region and is especially attractive in the context of Majorana research. Conductance measurement provides only partial information about nonlocal response composed from both electron-like and hole-like quasiparticle excitations. In this work, we show how a nonlocal shot noise measurement delivers a missing puzzle piece in NSN InAs nanowire-based devices. We demonstrate that in a trivial superconducting phase quasiparticle response is practically charge-neutral, dominated by the heat transport component with a thermal conductance being on the order of conductance quantum. This is qualitatively explained by numerous Andreev reflections of a diffusing quasiparticle, that makes its charge completely uncertain. Consistently, strong fluctuations and sign reversal are observed in the sub-gap nonlocal conductance, including occasional Andreev rectification signals. Our results prove conductance and noise as complementary measurements to characterize quasiparticle transport in superconducting proximity devices.

Original languageEnglish
Article number09LT04
Number of pages6
JournalSemiconductor Science and Technology
Volume36
Issue number9
Early online date6 Aug 2021
DOIs
Publication statusPublished - Sep 2021
MoE publication typeA1 Journal article-refereed

Keywords

  • shot noise
  • Andreev reflection
  • non-local transport
  • hybrid devices
  • Majorana zero modes
  • thermal conductance
  • SHOT-NOISE
  • REENTRANCE
  • TRANSPORT

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