Detecting Topological Phases in Cold Atoms

TL;DR

This paper proposes practical methods to detect topological phases, specifically Chern insulators, in cold atom systems by measuring Bloch eigenstates at symmetric Brillouin zone points, bypassing challenging Hall measurements.

Contribution

It introduces a novel approach linking topological insulators to quantum anomalous Hall systems, enabling detection via Bloch eigenstate measurements at symmetric points.

Findings

Topological phases can be identified by measuring Bloch eigenstates at symmetric BZ points.

Two experimental schemes, including spin-resolved Bloch oscillation, are feasible for cold atom detection.

The methods are practical under realistic experimental conditions.

Abstract

Chern insulators are band insulators which exhibit a gap in the bulk and gapless excitations in the edge. Detection of Chern insulators is a serious challenge in cold atoms since the Hall transport measurements are technically unrealistic for neutral atoms. By establishing a natural correspondence between the time-reversal invariant topological insulator and quantum anomalous Hall system, we show for a class of Chern insulators that the topology can be determined by only measuring Bloch eigenstates at highly symmetric points of the Brillouin zone (BZ). Furthermore, we introduce two experimental schemes including the spin-resolved Bloch oscillation to carry out the measurement. These schemes are highly feasible under realistic experimental conditions. Our results may provide a powerful tool to detect topological phases in cold atoms.