Spin squeezing in Bose-Einstein condensates: Limits imposed by decoherence and non-zero temperature

TL;DR

This paper investigates how particle losses and finite temperature affect the limits of spin squeezing in Bose-Einstein condensates, revealing new scaling laws and a dephasing mechanism that constrains quantum enhancement.

Contribution

It provides new analytical scaling laws for spin squeezing in realistic conditions, incorporating decoherence and thermal effects in a multimode framework.

Findings

Particle losses and temperature alter the optimal squeezing scaling.

Decoherence acts as a dephasing mechanism limiting squeezing.

Analytical expressions for squeezing in the thermodynamic limit are derived.

Abstract

We consider dynamically generated spin squeezing in interacting bimodal condensates. We show that particle losses and non-zero temperature effects in a multimode theory completely change the scaling of the best squeezing for large atom numbers. We present the new scalings and we give approximate analytical expressions for the squeezing in the thermodynamic limit. Besides reviewing our recent theoretical results, we give here a simple physical picture of how decoherence acts to limit the squeezing. We show in particular that under certain conditions the decoherence due to losses and non-zero temperatureacts as a simple dephasing.