Self-Pinning Transition of a Tonks-Girardeau Gas in a Bose-Einstein Condensate

TL;DR

This paper demonstrates that a Tonks-Girardeau gas immersed in a Bose-Einstein condensate can undergo a self-pinning transition to a Mott insulator state without external lattices, characterized by interspecies interactions and temperature.

Contribution

It introduces a novel phase transition mechanism for a TG gas in a BEC, with an effective model to predict the critical temperature and observable signatures.

Findings

Transition to a crystal-like Mott state without external lattice

Effective model accurately describes the pinned insulator phase

Critical temperature of the transition derived

Abstract

We show that a Tonks-Girardeau (TG) gas that is immersed in a Bose-Einstein condensate can undergo a transition to a crystal-like Mott state with regular spacing between the atoms without any externally imposed lattice potential. We characterize this phase transition as a function of the interspecies interaction and temperature of the TG gas, and show how it can be measured via accessible observables in cold atom experiments. We also develop an effective model that accurately describes the system in the pinned insulator state and which allows us to derive the critical temperature of the transition.