Entanglement spectrum: Identification of the transition from vortex-liquid to vortex-lattice state in a weakly interacting rotating Bose-Einstein condensate

TL;DR

This paper investigates the phase transition in a rotating Bose-Einstein condensate from vortex liquid to vortex lattice using entanglement spectrum analysis, providing a novel method to identify phase changes.

Contribution

It introduces entanglement spectrum analysis as a new approach to detect phase transitions in rotating BECs, highlighting differences in entanglement features across phases.

Findings

Entanglement spectrum changes clearly at the phase transition.

Disappearance of entanglement gap signals the transition on the sphere.

Decreased particle entanglement indicates the phase change.

Abstract

We use entanglement to investigate the transition from vortex liquid phase to vortex lattice phase in weakly interacting rotating Bose-Einstein condensate (BEC). Ground state entanglement spectrum is analyzed to distinguish these two different phases. For the torus geometry, the low-lying part of ground state entanglement spectrum, as well as the behavior of its lowest level change clearly when the transition occurs. For the sphere geometry, the disappearance of entanglement gap in the conformal limit (CL) can indicate this transition. We also show that the decrease of entanglement between particles can be regarded as a signal of the transition.