Anisotropic Coherence properties in a trapped quasi2D dipolar gas

Abstract

We consider a trapped quasi2D dipolar Bose Einstein condensate (q2D DBEC) with a polariza- tion tilted into the plane of motion. We show that by tilting the polarization axis, the coherence properties are anisotropic. Such a system will have density fluctuations whose amplitude strongly depend on their trap location relative to the polarization axis. Additionally, interference contrast will also be anisotropic despite an isotropic density profile. The anisotropy is related to a roton like mode that becomes unstable and supports local collapse along the polarization axis.