Transition from three- to two-dimensional Ising superconductivity in few-layer NbSe2 by proximity effect from van der Waals heterostacking

TL;DR

This paper reports the experimental discovery of Ising superconductivity in few-layer NbSe2 heterostructures with MoS2, revealing strong spin-orbit effects and potential for topological superconductivity.

Contribution

It demonstrates the transition from three-dimensional to two-dimensional Ising superconductivity in NbSe2 via van der Waals heterostacking with MoS2, a novel experimental observation.

Findings

Confirmation of 2D Ising superconductivity in NbSe2 heterostructures

Strong Ising spin-orbit correlations induce non-degenerate holes

Potential for realizing topological chiral superconductors

Abstract

We report the experimental observation of Ising superconductivity in 3-dimensional NbSe2 stacked with single-layer MoS2. The angular dependence of the upper critical magnetic field and the temperature dependence of the upper parallel critical field confirm the appearance of two-dimensional Ising superconductivity in the 3-dimensional NbSe2 with single-layer MoS2 overlay. We show that the superconducting phase has strong Ising spin-orbit correlations which make the holes spin non-degenerate. Our observation of Ising superconductivity in heterostructures of few-layer NbSe2 of thickness ~ 15 nm with single-layer MoS2 raises the interesting prospect of observing topological chiral superconductors with nontrivial Chern numbers in a momentum-space spin-split fermionic system.