Chiral topological phases in optical lattices without synthetic fields

TL;DR

This paper proposes a method to realize chiral topological phases in optical lattices using dipolar fermions in frustrated kagome lattices, avoiding synthetic fields and their associated heating issues.

Contribution

It demonstrates, through numerical modeling, that dipolar interactions in a kagome lattice can spontaneously break time reversal symmetry to produce a topological Mott insulator.

Findings

Interaction-driven topological phase identified in dipolar fermions

Spontaneous time reversal symmetry breaking observed

Feasible experimental parameters estimated for realization

Abstract

Synthetic fields applied to ultracold quantum gases can realize topological phases that transcend conventional Bose and Fermi-liquid paradigms. Raman laser beams in particular are under scrutiny as a route to create synthetic fields in neutral gases to mimic ordinary magnetic and electric fields acting on charged matter. Yet external laser beams can impose heating and losses that make cooling into many-body topological phases challenging. We propose that atomic or molecular dipoles placed in optical lattices can realize a topological phase without synthetic fields by placing them in certain frustrated lattices. We use numerical modeling on a specific example to show that the interactions between dipolar fermions placed in a kagome optical lattice spontaneously break time reversal symmetry to lead to a topological Mott insulator, a chiral topological phase generated entirely by interactions. We estimate realistic entropy and trapping parameters to argue that this intriguing phase of matter can be probed with quantum gases using a combination of recently implemented technologies.