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 language | English |
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Article number | 09LT04 |
Number of pages | 6 |
Journal | Semiconductor Science and Technology |
Volume | 36 |
Issue number | 9 |
Early online date | 6 Aug 2021 |
DOIs | |
Publication status | Published - Sept 2021 |
MoE publication type | A1 Journal article-refereed |
Keywords
- shot noise
- Andreev reflection
- non-local transport
- hybrid devices
- Majorana zero modes
- thermal conductance
- SHOT-NOISE
- REENTRANCE
- TRANSPORT