Engineering chiral topological superconductivity in twisted Ising superconductors

TL;DR

This paper proposes a method to realize chiral topological superconductivity in twisted bilayer Ising superconductors with ferromagnetic buffers, predicting observable signatures like quantized thermal Hall effect.

Contribution

It introduces a theoretical framework for engineering chiral topological superconductivity in twisted Ising superconductor heterostructures with ferromagnetic layers.

Findings

Topological superconducting gap can exceed 0.1 meV.

Quantized thermal Hall transport is a potential experimental signature.

Chiral topological phases can be realized in NbSe2/CrCl3/NbSe2 heterostructures.

Abstract

Van der Waals materials like NbSe$_2$ or TaS$_2$ have demonstrated Ising superconductivity down to atomically thin layers. Due to the spin-orbit coupling, these superconductors have the in-plane upper critical magnetic field far beyond the Pauli limit. We theoretically demonstrate that, twisted bilayer Ising superconductors separated by a ferromagnetic buffer layer can naturally host chiral topological superconductivity with Chern numbers, which can be realized in heterostructures like $\mathrm{NbSe_2/CrCl_3/NbSe_2}$. Under appropriate experimental conditions the topological superconducting gap can reach $>0.1$ meV, leading to readily observable signatures such as the quantized thermal Hall transport at low temperatures.