Anisotropic Coherence properties in a trapped quasi2D dipolar gas

TL;DR

This paper investigates how tilting the polarization axis in a trapped quasi2D dipolar Bose-Einstein condensate induces anisotropic coherence and density fluctuation properties, linked to roton-like excitations and local collapse phenomena.

Contribution

It demonstrates that polarization tilt causes anisotropic coherence and density fluctuations, revealing the role of roton-like modes in stability and collapse behavior.

Findings

Coherence properties become anisotropic with polarization tilt

Density fluctuations depend on trap location relative to polarization axis

Roton-like mode instability supports local collapse along polarization axis

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.