Macroscopic Quantum Tunneling in Superconducting Junctions of \beta-Ag$_{2}$Se Topological Insulator Nanowire

TL;DR

This study demonstrates macroscopic quantum tunneling in superconducting junctions made from -AgSe topological insulator nanowires, highlighting their potential for quantum computing applications.

Contribution

It reports the fabrication and characterization of TI nanowire-based Josephson junctions exhibiting quantum tunneling behavior up to 0.8 K, a novel observation for such systems.

Findings

Macroscopic quantum tunneling observed in TI nanowire junctions

Critical current decreases with magnetic field

Junctions suitable for quantum bit development

Abstract

We report on the fabrication and electrical transport properties of superconducting junctions made of \beta-Ag$_{2}$Se topological insulator (TI) nanowires in contact with Al superconducting electrodes. The temperature dependence of the critical current indicates that the superconducting junction belongs to a short and diffusive junction regime. As a characteristic feature of the narrow junction, the critical current decreases monotonously with increasing magnetic field. The stochastic distribution of the switching current exhibits the macroscopic quantum tunneling behavior, which is robust up to T = 0.8 K. Our observations indicate that the TI nanowire-based Josephson junctions can be a promising building block for the development of nanohybrid superconducting quantum bits.