The cold-atom elevator: From edge-state injection to the preparation of fractional Chern insulators

TL;DR

This paper proposes a novel method using optical box traps to inject particles and cool atomic gases, enabling the preparation and manipulation of topological and fractional Chern insulating states in optical lattices.

Contribution

It introduces a new open-system approach with reservoir engineering for preparing topological quantum states in ultracold atomic gases.

Findings

Energy-selective chiral edge currents can be activated.

Fractional Chern insulator ground states can be prepared.

A practical evaporative-cooling scheme effectively cools gases into topological states.

Abstract

Optical box traps for cold atoms offer new possibilities for quantum-gas experiments. Building on their exquisite spatial and temporal control, we propose to engineer system-reservoir configurations using box traps, in view of preparing and manipulating topological atomic states in optical lattices. First, we consider the injection of particles from the reservoir to the system: this scenario is shown to be particularly well suited to activate energy-selective chiral edge currents, but also, to prepare fractional Chern insulating ground states. Then, we devise a practical evaporative-cooling scheme to effectively cool down atomic gases into topological ground states. Our open-system approach to optical-lattice settings provides a new path for the investigation of ultracold quantum matter, including strongly-correlated and topological phases.