Crystalline Anisotropic Topological Superconductivity in Planar Josephson Junctions

TL;DR

This paper explores how crystalline anisotropy influences topological phase transitions in planar Josephson junctions, revealing ways to electrically control Majorana states for quantum computing applications.

Contribution

It introduces a theoretical framework showing how magnetic field orientation and crystallography affect topological superconductivity in planar JJs, enabling optimized Majorana state stability.

Findings

Magnetic field and crystallographic orientation interplay affects topological phases.

Electrical tuning can switch between different symmetry classes.

Guidelines for engineering stable Majorana bound states.

Abstract

We theoretically investigate the crystalline anisotropy of topological phase transitions in phase-controlled planar Josephson junctions (JJs) subject to spin-orbit coupling and in-plane magnetic fields. It is shown how topological superconductivity (TS) is affected by the interplay between the magnetic field and the orientation of the junction with respect to its crystallographic axes. This interplay can be used to electrically tune between different symmetry classes in a controlled fashion and thereby optimize the stability and localization of Majorana bound states in planar Josephson junctions. Our findings can be used as a guide for achieving the most favorable conditions when engineering TS in planar JJs and can be particularly relevant for setups containing non-collinear junctions which have been proposed for performing braiding operations on multiple Majorana pairs.