Angular collapse of dipolar Bose-Einstein condensates

TL;DR

This paper investigates the structure and collapse dynamics of dipolar Bose-Einstein condensates near their instability threshold, highlighting the emergence of biconcave density profiles and angular roton modes as key features.

Contribution

It introduces the concept of angular collapse and biconcave structures in dipolar BECs, providing experimental signatures and analyzing collapse dynamics.

Findings

Identification of local collapse signatures in stability diagrams

Observation of nontrivial angular distributions during collapse

Evidence of biconcave density structures in dipolar BECs

Abstract

We explore the structure and dynamics of dipolar Bose-Einstein condensates (DBECs) near their threshold for instability. Near this threshold a DBEC may exhibit nontrivial, biconcave density distributions, which are associated with instability against collapse into "angular roton" modes. Here we discuss experimental signatures of these novel features. In the first, we infer local collapse of the DBEC from the experimental stability diagram. In the second, we explore the dynamics of collapse and find that a nontrivial angular distribution is a signature of the DBEC possessing a biconcave structure.