Zero bias conductance peak in InAs nanowire coupled to superconducting electrodes

TL;DR

This study observes a zero-bias conductance peak in InAs nanowires coupled to superconductors, demonstrating its dependence on temperature, bias voltage, and magnetic field, consistent with reflectionless tunneling theory.

Contribution

It provides experimental evidence of the ZBCP in InAs nanowires and links it to reflectionless tunneling, expanding understanding of electron-hole coherence in hybrid nanostructures.

Findings

ZBCP suppressed by increasing temperature and bias voltage

Magnetic field diminishes ZBCP at flux quantum h/2e

Results align with reflectionless tunneling theory

Abstract

We report the occurrence of the zero-bias conductance peak (ZBCP) in an InAs nanowire coupled to PbIn superconductors with varying temperature, bias voltage, and magnetic field. The ZBCP is suppressed with increasing temperature and bias voltage above the Thouless energy of the nanowire. Applying a magnetic field also diminishes the ZBCP when the resultant magnetic flux reaches the magnetic flux quantum h/2e. Our observations are consistent with theoretical expectations of reflectionless tunneling, in which the phase coherence between an electron and its Andreev-reflected hole induces the ZBCP as long as time-reversal symmetry is preserved.