Quantized single-particle Thouless pump induced by topology transfer from a Chern insulator at finite temperature

TL;DR

This paper demonstrates that coupling a finite-temperature Chern insulator to an auxiliary lattice can induce quantized particle transport, preserving topological invariants even at high temperatures, as shown in a Rice-Mele model.

Contribution

It introduces a method to achieve quantized transport at finite temperature via topology transfer from a Chern insulator to an auxiliary system.

Findings

Quantized transport persists at finite temperature exceeding the band gap.

Coupling to an auxiliary lattice induces quantized particle movement.

Finite-temperature topological invariants can be realized in practical models.

Abstract

Quantized particle or spin transport upon cyclic parameter variations, determined by topological invariants, is a key signature of Chern insulators in the ground state. While measurable many-body observables exist that preserve the integrity of topological invariants also at finite temperature, quantized transport is generically lost. We here show that a coupling of a one-dimensional Chern insulator at arbitrary finite temperature to an auxiliary lattice can induce quantized transport determined by the finite-temperature invariant. We show for the example of a Rice-Mele model that the spatial distribution of a single particle in the auxiliary chain moves by a quantized number of unit cells in a Thouless cycle when subtracting a spatially homogeneous offset even at a temperature exceeding the band gap.