Laughlin's topological charge pump in an atomic Hall cylinder

TL;DR

This paper demonstrates Laughlin's topological charge pump using ultracold dysprosium atoms, encoding the quantum Hall cylinder in atomic spin states, showcasing topological quantum matter in a controllable atomic system.

Contribution

It experimentally realizes Laughlin's thought experiment with ultracold atoms, linking topological quantum Hall effects to atomic spin and laser-induced couplings.

Findings

Observation of quantized atomic motion consistent with topological charge pumping

Implementation of spin-orbit coupling to simulate axial magnetic fields

Potential to explore strongly-correlated topological phases

Abstract

The quantum Hall effect occuring in two-dimensional electron gases was first explained by Laughlin, who envisioned a thought experiment that laid the groundwork for our understanding of topological quantum matter. His proposal is based on a quantum Hall cylinder periodically driven by an axial magnetic field, resulting in the quantized motion of electrons. We realize this milestone experiment with an ultracold gas of dysprosium atoms, the cyclic dimension being encoded in the electronic spin and the axial field controlled by the phases of laser-induced spin-orbit couplings. Our experiment provides a straightforward manifestation of the non-trivial topology of quantum Hall insulators, and could be generalized to strongly-correlated topological systems.