Direct imaging of topological edge states in cold-atom systems

TL;DR

This paper proposes a novel optical-lattice-based method to directly visualize and analyze topological edge states in cold-atom systems, enabling new insights into topological phases through dynamic imaging.

Contribution

It introduces a new experimental scheme for imaging topological edge modes in cold-atom systems by shaping and observing atomic gases, advancing topological matter detection.

Findings

Method allows direct visualization of edge mode propagation.

Enables measurement of angular velocity and spin structure.

Applicable to various atomic topological phases.

Abstract

Detecting topological order in cold-atom experiments is an ongoing challenge, the resolution of which offers novel perspectives on topological matter. In material systems, unambiguous signatures of topological order exist for topological insulators and quantum Hall devices. In quantum Hall systems, the quantized conductivity and the associated robust propagating edge modes - guaranteed by the existence of non-trivial topological invariants - have been observed through transport and spectroscopy measurements. Here, we show that optical-lattice-based experiments can be tailored to directly visualize the propagation of topological edge modes. Our method is rooted in the unique capability for initially shaping the atomic gas, and imaging its time-evolution after suddenly removing the shaping potentials. Our scheme, applicable to an assortment of atomic topological phases, provides a method for imaging the dynamics of topological edge modes, directly revealing their angular velocity and spin structure.