Gate-controlled supercurrent in epitaxial Al/InAs nanowires

TL;DR

This paper demonstrates gate-controlled supercurrent in epitaxial Al/InAs nanowires, revealing a new mechanism for superconducting field effect transistors with potential for low-power electronics.

Contribution

First realization of gate-controlled supercurrent in an epitaxial superconductor shell on InAs nanowires, advancing understanding of the microscopic mechanism involved.

Findings

Supercurrent can be switched to the normal state with ±23 V gate voltage.

Temperature and magnetic field studies suggest hot electron injection is not the sole mechanism.

Epitaxial Al shell enables effective supercurrent control via gating.

Abstract

Gate-controlled supercurrent (GCS) in superconductor nanobridges has recently attracted attention as a means to create superconducting field effect transistors. Despite the clear advantage for applications with low power consumption and high switching speeds, the microscopic mechanism of the field effect is still under debate. In this work, we realize GCS for the first time in an epitaxial superconductor, which is created as a shell on an InAs nanowire. We show that the supercurrent in the epitaxial Al layer can be switched to the normal state by applying $\simeq\pm$ 23$\,$V on a bottom gate insulated from the nanowire by a crystalline hBN layer. Our extensive study on the temperature and magnetic field dependencies of GCS suggests that hot electron injection alone cannot explain our experimental findings.