arXiv:0803.3771 · Physical Review A
Optical lattice quantum Hall effect
Rebecca N Palmer, Alexander Klein, Dieter Jaksch
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 $\ensuremath{\alpha}$ is close to a simple rational number [R. N. Palmer and D. Jaksch, 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 $\ensuremath{\alpha}=1/2$ 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 $\ensuremath{\alpha}$. 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 $\ensuremath{\alpha}$.