Topological superconductivity with large Chern numbers in a ferromagnetic metal-superconductor heterostructure

TL;DR

This paper explores topological superconductivity in a ferromagnetic metal-superconductor heterostructure, revealing multiple Chern numbers, large topological states, and associated edge states with potential for anomalous thermal Hall effects.

Contribution

It demonstrates the emergence of rich topological phases with large Chern numbers due to interface Rashba and Dresselhaus spin-orbit couplings, including a state with Chern number four.

Findings

Identification of five distinct topological phases with different Chern numbers

Discovery of a topological state with Chern number four

Edge states localized mainly on the ferromagnetic layer

Abstract

The ferromagnetic metal-superconductor heterostructure with interface Rashba spin-orbit hopping is a promising candidate for topological superconductivity. We study the interplay between the interface Rashba hopping and the intrinsic Dresselhaus spin-orbit coupling in this heterostructure, and demonstrate rich topological phases with five distinct Chern numbers. In particular, we find a topological state with a Chern number as large as four in the parameter space of the heterostructure. We calculate the Berry curvatures that construct the Chern numbers, and show that these Berry curvatures induce anomalous thermal Hall transport of the superconducting quasiparticles. We reveal chiral edge states in the topological phases, as well as helical edge states in the trivial phase, and show that the wave functions of these edge states mostly concentrate on the ferrometal layer of the heterostructure.