Projected spin texture as a bulk indicator of fragile topology

TL;DR

This paper establishes a theoretical link between spin textures and band topology, proposing that spin gap measurements can serve as bulk indicators of fragile topological phases in certain symmetry contexts.

Contribution

It introduces a formal map connecting projected spin textures to Wilson loop winding, providing a new bulk diagnostic for fragile topology.

Findings

Spin gap can indicate fragile topology in specific symmetry settings.

A formal relationship between spin textures and Wilson loop winding is established.

The results suggest practical bulk measurements for fragile topological phases.

Abstract

We study the relationship between projected momentum-space spin textures and Wilson loop winding, proving a map between band topology of and spin topology in certain restricted symmetry settings, relevant to fragile topology. Our results suggest that the spin gap may act as a smoking gun bulk indicator for fragile topology within specific scenarios.