Josephson Diode Effect in Topological Superconductor

TL;DR

This paper explores how the Josephson diode effect varies in topological superconductors, revealing that while topological phases can enhance diode efficiency, the effect is not solely determined by topological states and can serve as a phase indicator.

Contribution

The study provides a detailed analysis of the Josephson diode effect in topological superconductors, highlighting its nuanced dependence on topological phases and potential as a phase indicator.

Findings

Higher diode efficiency in topological phases compared to trivial phases.

Diode effect is not solely dependent on Majorana bound states.

Significant diode effect occurs near topological phase transition boundaries.

Abstract

We investigate the Josephson diode effect (JDE) in topological Josephson junctions. By both analytic and numerical calculations, we find that while a Josephson junction in the topological phase may exhibit higher diode efficiency compared to that in the trivial phase, this behavior is not universal. The presence of Majorana bound states is not a sufficient condition for a large diode effect. Furthermore, the diode efficiency undergoes substantial changes only in specific regions along the topological phase transition boundary, and a significant diode effect does coincide with the topological phases. Thereby our paper suggests the utilization of topological superconductivity for enhanced JDE, and also the Josephson diode effect may serve as an indicator for topological superconductor phase. These results suggest a nuanced relationship between the topological aspects of Josephson junctions and Josephson diode effect.