Squeezed Ground States in a Spin-1 Bose-Einstein Condensate

TL;DR

This paper demonstrates the creation of spin squeezed ground states in a spin-1 Bose-Einstein condensate near a quantum critical point, achieving enhanced measurement precision with stable squeezing over time.

Contribution

It introduces a method to generate time-stationary squeezed ground states in a spinor BEC near a quantum phase transition, differing from non-equilibrium approaches.

Findings

Achieved 6-8 dB metrological improvement.

Maintained constant squeezing angle over 2 seconds.

Produced squeezed states as ground states, not transient.

Abstract

We generate spin squeezed ground states in an atomic spin-1 Bose-Einstein condensate tuned nearthe quantum critical point between the polar and ferromagnetic quantum phases of the interactingspin ensemble. In contrast to typical non-equilibrium methods for preparing atomic squeezed statesby quenching through a quantum phase transition, squeezed ground states are time-stationary andremain squeezed for the lifetime of the condensate. A squeezed ground state with a metrologicalimprovement up to 6-8 dB and a constant squeezing angle maintained over 2 s is demonstrated.