Rydberg-Atom Quantum Simulation and Chern Number Characterization of a Topological Mott Insulator

TL;DR

This paper proposes a realistic scheme for simulating a topological Mott insulator with cold atoms in a honeycomb lattice, demonstrating a dynamically generated quantum anomalous Hall phase characterized by a non-zero Chern number.

Contribution

It introduces a method to realize a topological Mott insulator using Rydberg-dressed cold atoms, combining mean-field theory and experimental techniques.

Findings

Identification of a quantum anomalous Hall phase driven by interactions

Numerical calculation confirming the topological nature via Chern number

Proposal of an experimental scheme using Rydberg-dressed atoms

Abstract

In this work we consider a system of spinless fermions with nearest and next-to-nearest neighbor repulsive Hubbard interactions on a honeycomb lattice, and propose and analyze a realistic scheme for analog quantum simulation of this model with cold atoms in a two-dimensional hexagonal optical lattice. To this end, we first derive the zero-temperature phase diagram of the interacting model within a mean-field theory treatment. We show that besides a semi-metallic and a charge-density-wave ordered phase, the system exhibits a quantum anomalous Hall phase, which is generated dynamically, i.e. purely as a result of the repulsive fermionic interactions and in the absence of any external gauge fields. We establish the topological nature of this dynamically created Mott insulating phase by the numerical calculation of a Chern number. Based on the knowledge of the mean-field phase diagram, we then discuss in detail how the interacting Hamiltonian can be engineered effectively by state-of-the-art experimental techniques for laser-dressing of cold fermionic ground-state atoms with electronically excited Rydberg states that exhibit strong dipolar interactions.