Topological Superconductivity in Monolayer T$_{\textrm{d}}$-MoTe$_2$

TL;DR

This paper proposes that applying an in-plane magnetic field to monolayer T$_{ extrm{d}}$-MoTe$_2$, a gate-tunable 2D superconductor with in-plane polar axis, can induce topological superconductivity through the interplay of Zeeman coupling and Ising plus in-plane SOC.

Contribution

It demonstrates a novel method to realize topological superconductivity in monolayer T$_{ extrm{d}}$-MoTe$_2$ using in-plane magnetic fields and SOC effects.

Findings

In-plane magnetic field beyond Pauli limit induces topological superconductivity.

Ising plus in-plane SOC enables effective $p_x+ip_y$ pairing.

Proposes a feasible way to realize topological superconductivity in 2D materials.

Abstract

Topological superconductivity has attracted significant attention due to its potential applications in quantum computation, but its experimental realization remains challenging. Recently, monolayer T$_{\textrm{d}}$-MoTe$_2$ was observed to exhibit gate tunable superconductivity, and its in-plane upper critical field exceeds the Pauli limit. Here, we show that an in-plane magnetic field beyond the Pauli limit can drive the superconducting monolayer T$_{\textrm{d}}$-MoTe$_2$ into a topological superconductor. The topological superconductivity arises from the interplay between the in-plane Zeeman coupling and the unique \emph{Ising plus in-plane SOC} in the monolayer T$_{\textrm{d}}$-MoTe$_2$. The \emph{Ising plus in-plane SOC} plays the essential role to enable the effective $p_x+ip_y$ pairing. Importantly, as the essential \emph{Ising plus in-plane SOC} in the monolayer T$_{\textrm{d}}$-MoTe$_2$ is generated by an in-plane polar field, our proposal demonstrates that applying an in-plane magnetic field to a gate tunable 2D superconductor with an in-plane polar axis is a feasible way to realize topological superconductivity.