Edge supercurrent in Josephson junctions based on topological materials

TL;DR

This paper reviews recent theoretical and experimental progress on edge supercurrents and quantum interference patterns in Josephson junctions made from topological materials, highlighting their significance for topological quantum computing.

Contribution

It provides a comprehensive overview of the latest advancements in understanding edge supercurrents and interference phenomena in topological material-based Josephson junctions.

Findings

Observation of unique interference patterns like Fraunhofer and $\Phi_0$-periodic oscillations.

Identification of different Andreev reflection mechanisms influencing supercurrents.

Insights into the role of topological states in superconducting quantum interference.

Abstract

The interplay between novel topological states and superconductivity has garnered substantial interest due to its potential for topological quantum computing. The Josephson effect serves as a useful probe for edge superconductivity in these hybrid topological materials. In Josephson junctions based on topological materials, supercurrents exhibit unique quantum interference patterns, including the conventional Fraunhofer oscillations, the $\Phi_0$-periodic oscillation, and the $2\Phi_0$-periodic oscillation in response to the external magnetic field ($\Phi_0 = h/2e$ is the flux quantum, $h$ the Planck constant, and $e$ the electron charge). These interference patterns stem from varied Andreev reflection mechanisms and the associated current density profiles. This review seeks to comprehensively examine the theoretical and experimental advancements in understanding the quantum interference patterns of edge supercurrents in Josephson junctions based on quantum spin Hall, quantum Hall, and quantum anomalous Hall systems.