Large Andreev bound state zero bias peaks in a weakly dissipative environment

TL;DR

This paper investigates zero bias peaks in InAs-Al nanowire devices, revealing how environmental Coulomb blockade influences their temperature dependence and distinguishes them from Fermi-liquid behavior.

Contribution

It demonstrates the impact of environmental Coulomb blockade on Andreev bound states and zero bias peaks in weakly dissipative environments, highlighting deviations from conventional Fermi-liquid behavior.

Findings

Large ZBPs can be tuned to zero bias with gate voltage or magnetic field.

Environmental Coulomb blockade causes non-Fermi liquid temperature dependence.

ZBP behavior varies with temperature, showing height increase or peak splitting.

Abstract

We study Andreev bound states in hybrid InAs-Al nanowire devices. The energy of these states can be tuned to zero by gate voltage or magnetic field, revealing large zero bias peaks (ZBPs) near 2e^2/h in tunneling conductance. Probing these large ZBPs using a weakly dissipative lead reveals non-Fermi liquid temperature (T) dependence due to environmental Coulomb blockade (ECB), an interaction effect from the lead acting on the nanowire junction. By increasing T, these large ZBPs either show a height increase or a transition from split peaks to a ZBP, both deviate significantly from non-dissipative devices where a Fermi-liquid T dependence is revealed. Our result demonstrates the competing effect between ECB and thermal broadening on Andreev bound states.