Dimensional crossover and cold-atom realization of topological Mott insulators

TL;DR

This paper proposes a cold-atom experimental setup to observe a dimensional crossover from quantum spin Hall insulators to strong topological insulators, and explores interaction-driven topological Mott insulators.

Contribution

It introduces a method to realize and study topological Mott insulators through tunable dimensional crossover and interactions in cold-atom systems.

Findings

Proposes a cold-atom setup for dimensional crossover from 2D to 3D topological phases.

Identifies conditions for realizing topological Mott insulators with interactions.

Provides a pathway for experimental investigation of exotic topological states.

Abstract

We propose a cold-atom setup which allows for a dimensional crossover from a two-dimensional quantum spin Hall insulating phase to a three-dimensional strong topological insulator by tuning the hopping between the layers. We further show that additional Hubbard onsite interactions can give rise to spin liquid-like phases: weak and strong topological Mott insulators. They represent the celebrated paradigm of a quantum state of matter which merely exists because of the interplay of the non-trivial topology of the band structure and strong interactions. While the theoretical understanding of this phase has remained elusive, our proposal shall help to shed some light on this exotic state of matter by paving the way for a controlled experimental investigation in optical lattices.