Dissipative preparation of fractional Chern insulators

TL;DR

This paper demonstrates that dissipative quantum dynamics can be used to prepare fractional Chern insulator states, like Laughlin states, with high fidelity in certain regimes, advancing the goal of realizing topological phases in quantum simulators.

Contribution

It shows how to engineer dissipative processes to reliably produce fractional quantum Hall states in lattice models, providing a new method for topological state preparation.

Findings

Laughlin states can be approximately prepared via dissipation in the Hofstadter model.

Steady states closely resemble fractional quantum Hall states under certain conditions.

Robustness of fractional state overlap observed for specific flux densities.

Abstract

We report on the numerically exact simulation of the dissipative dynamics governed by quantum master equations that feature fractional quantum Hall states as unique steady states. In particular, for the paradigmatic Hofstadter model, we show how Laughlin states can be to good approximation prepared in a dissipative fashion from arbitrary initial states by simply pumping strongly interacting bosons into the lowest Chern band of the corresponding single-particle spectrum. While pure (up to topological degeneracy) steady states are only reached in the low-flux limit or for extended hopping range, we observe a certain robustness regarding the overlap of the steady state with fractional quantum Hall states for experimentally well-controlled flux densities. This may be seen as an encouraging step towards addressing the long-standing challenge of preparing strongly correlated topological phases in quantum simulators.