Josephson Junction through a Disordered Topological Insulator with Helical Magnetization

TL;DR

This paper investigates how supercurrent and vortices behave in a disordered topological insulator Josephson junction with helical magnetization, revealing controllable 0-π transitions and vortex nucleation influenced by various parameters.

Contribution

It demonstrates the existence of supercurrent 0-π crossovers and vortex nucleation in a disordered topological insulator junction with helical magnetization, highlighting controllability via phase difference and material parameters.

Findings

Supercurrent exhibits 0-π crossovers depending on junction parameters.

Proximity-induced vortices are nucleated along the junction width.

Vortex positions and number can be manipulated by phase difference and magnetization parameters.

Abstract

We study supercurrent and proximity vortices in a Josephson junction made of disordered surface states of a three-dimensional topological insulator with a proximity induced in-plane helical magnetization. In a regime where the rotation period of helical magnetization is larger than the junction width, we find supercurrent 0-{\pi} crossovers as a function of junction thickness, magnetization strength, and parameters inherent to the helical modulation and surface states. The supercurrent reversals are associated with proximity induced vortices, nucleated along the junction width, where the number of vortices and their locations can be manipulated by means of the superconducting phase difference and the parameters mentioned above.