Limit of Spin Squeezing in Finite Temperature Bose-Einstein Condensates

TL;DR

This paper demonstrates that in finite temperature Bose-Einstein condensates, the maximum achievable spin squeezing has a finite limit as atom number grows, determined by the initial non-condensed fraction.

Contribution

It establishes a fundamental limit on spin squeezing in finite temperature BECs, linking it to the initial non-condensed fraction.

Findings

Maximum spin squeezing is bounded at finite temperature.

The limit is determined by the initial non-condensed fraction.

The bound applies as atom number approaches infinity.

Abstract

We show that, at finite temperature, the maximum spin squeezing achievable using interactions in Bose-Einstein condensates has a finite limit when the atom number $N\to \infty$ at fixed density and interaction strength. We calculate the limit of the squeezing parameter for a spatially homogeneous system and show that it is bounded from above by the initial non-condensed fraction.