Gate-controlled supercurrent reversal in MoS$_2$-based Josephson junctions

TL;DR

This paper explores how gate voltage-induced doping in MoS$_2$ monolayers can reversibly switch the supercurrent direction in Josephson junctions, driven by spin-orbit coupling and doping-dependent Fermi properties.

Contribution

It demonstrates a novel doping-controlled supercurrent reversal mechanism in MoS$_2$ Josephson junctions, differing from traditional superconductor/ferromagnet systems.

Findings

Supercurrent reversal can be achieved by gate voltage tuning.

Doping affects the amplitude and period of supercurrent oscillations.

Spin-orbit interaction influences the supercurrent behavior.

Abstract

Motivated by recent experiments revealing superconductivity in MoS$_2$, we investigate the Josephson effect in the monolayer MoS$_2$ at the presence of an exchange splitting. We show that the supercurrent reversal known as $0-\pi$ transition can occur by varying the doping via gate voltages. This is in contrast to common superconductor/ferromagnet/superconductor junctions in which successive $0-\pi$ transition take place with the variation of junction length or temperature. In fact for the case of MoS$_2$ we find that both the amplitude and the period of oscillations show a dependence on the doping which explains the predicted doping induced supercurrent reversal. These effects comes from the dependence of density and Fermi velocity on the doping strength beside the intrinsic spin splitting in the valence band which originates from spin-orbit interaction.