Anomalous behavior of spin systems with dipolar interactions
In this project, we studied the properties of spin systems realized by cold polar molecules interacting via dipole-dipole interactions in two dimensions. Using a spin wave theory, that allows for the full treatment of the characteristic long-distance tail of the dipolar interaction, we found several anomalous features in the ground state correlations and the spin wave excitation spectrum, which are absent in their counterparts with short-range interaction. The most striking consequence is the existence of true long-range order at finite temperature for a two-dimensional phase with a broken U(1) symmetry.
Driving Dipolar Fermions into the Quantum Hall Regime
A new method to drive a system of neutral dipolar fermions into the lowest Landau level regime was proposed. By employing adiabatic spin-flip processes in combination with a diabatic transfer, the fermions are pumped to higher orbital angular momentum states in a repeated scheme that allows for the precise control over the final angular momentum. A simple analytical model was derived to quantify the transfer and compare the approach to rapidly rotating systems. Numerical simulations of the transfer process were performed for small, interacting systems.