Spin squeezing by tensor twisting and Lipkin-Meshkov-Glick dynamics in a toroidal Bose-Einstein condensate with spatially modulated nonlinearity

TL;DR

This paper presents a method to generate spin-squeezing in a Bose-Einstein condensate's orbital motion using spatially modulated nonlinear interactions in a toroidal trap, implementing Lipkin-Meshkov-Glick dynamics.

Contribution

It introduces a novel scheme for spin-squeezing via tensor twisting and LMG dynamics in a BEC with spatially modulated nonlinearity, enabling control over different squeezing regimes.

Findings

Realizes one-axis and two-axis twisting regimes.

Demonstrates control over the twisting tensor parameters.

Provides a natural implementation of the LMG model.

Abstract

We propose a scheme for spin-squeezing in the orbital motion of a Bose-Einstein condensate (BEC) in a toroidal trap. A circular lattice couples two counter-rotating modes and squeezing is generated by the nonlinear interaction spatially modulated at half the lattice period. By varying the amplitude and phase of the modulation, various cases of the twisting tensor can be directly realized, leading to different squeezing regimes. These include one-axis twisting and the two-axis counter-twisting which are often discussed as the most important paradigms for spin squeezing. Our scheme naturally realizes the Lipkin-Meshkov-Glick model with the freedom to vary all its parameters simultaneously.