Optical lattice quantum Hall effect

TL;DR

This paper investigates topological quantum Hall states in an optical lattice with interacting bosons under a strong artificial magnetic field, revealing novel phases, vortex lattice behavior, and measurement techniques for state identification.

Contribution

It extends previous work by exploring topological states at various flux densities, including vortex lattice phases and methods for experimental detection.

Findings

Observation of Laughlin and Read-Rezayi states in optical lattices

Identification of a striped vortex lattice phase near alpha=1/2

Proposed measurement techniques using noise correlations and spatial functions

Abstract

We explore the behavior of interacting bosonic atoms in an optical lattice subject to a large artificial magnetic field. We extend earlier investigations of this system where the number of magnetic flux quanta per unit cell alpha is close to a simple rational number [Phys. Rev. Lett. 96, 180407 (2006)]. Interesting topological states such as the Laughlin and Read-Rezayi states can occur even if the atoms experience a weak trapping potential in one direction. An explicit numerical calculation near alpha = 1/2 shows that the system exhibits a striped vortex lattice phase of one species, which is analogous to the behavior of a two-species system for small alpha. We also investigate methods to probe the encountered states. These include spatial correlation functions and the measurement of noise correlations in time of flight expanded atomic clouds. Characteristic differences arise which allow for an identification of the respective quantum Hall states. We furthermore discuss that a counterintuitive flow of the Hall current occurs for certain values of alpha.