Skyrmion spin texture in ferromagnetic semiconductor-superconductor heterostructures

TL;DR

This paper derives a classification of spin Skyrmion textures in 2D topological superconductors made from ferromagnetic and semiconductor-superconductor heterostructures, linking topological phases to measurable spin textures.

Contribution

It introduces a Skyrmion number classification for topological superconductors, providing a physically intuitive and measurable topological invariant.

Findings

Non-zero Skyrmion number correlates with topological phase

Skyrmion classification extends to 1D topological superconductors

Skyrmion number can be measured via spin-sensitive imaging

Abstract

We provide a derivation of a spin Skyrmion number classification for two-dimensional topological superconductors constructed from ferromagnetic and Rashba spin-orbit coupled semiconductor-superconductor heterostructures. We show that in the non-trivial topological phase, characterized by a non-zero Chern number, there is always a topological spin texture in the occupied bands represented by a Skyrmion number. The Skyrmion number has the advantage of being both physically intuitive and directly measurable using spin-sensitive band structure imaging techniques. In addition, we show that the Skyrmion classification can be extended to the equivalent one-dimensional topological superconductors.