Response of fermions in Chern bands to spatially local quenches

TL;DR

This paper investigates how fermions in Chern bands respond dynamically to local quenches, revealing edge chiral responses and propagation behaviors that can be used to identify topological properties.

Contribution

It demonstrates the manifestation of chiral edge responses in Chern bands after local quenches and explores how to simulate half-filling in trapped systems.

Findings

Chiral edge responses are observable after local quenches.

Propagation velocities depend on the bulk band gap.

Edge responses can be mimicked in trapped fermion systems.

Abstract

We study the dynamical evolution of Chern-band systems after subjecting them to local quenches. For open-boundary systems, we show for half-filling that the chiral nature of edge states is manifested in the time-dependent chiral response to local density quenches on the edge. In the presence of power-law traps, we show how to mimic the half-filling situation by choosing the appropriate number of fermions depending on the trap size, and explore chiral responses of edges to local quenches in such a configuration. We find that perturbations resulting from the quenches propagate at different group velocities depending on the bulk band gap. Our results provide different routes to check dynamically the non-trivial nature of Chern bands.