Quantum phase diffusions of a spinor condensate

TL;DR

This paper analyzes quantum phase fluctuations in a spinor-1 Bose-Einstein condensate, revealing the stability of the mean field ground state and the dynamics of symmetry recovery related to atom number and magnetization.

Contribution

It provides an exact ground state distribution of phase fluctuations for ferromagnetic interactions in spinor condensates, highlighting stability and symmetry dynamics.

Findings

Exact phase fluctuation distribution obtained

Mean field ground state is stable against fluctuations

Symmetries related to atom number and magnetization are dynamically recovered

Abstract

We discuss the quantum phases and their diffusion in a spinor-1 atomic Bose-Einstein condensate. For ferromagnetic interactions, we obtain the exact ground state distribution of the phase fluctuations corresponding to the total atom number ($N$), the magnetization (${\cal M}$), and the alignment (or hypercharge) ($Y$) of the system. The mean field ground state is shown to be stable against these fluctuations, which dynamically recover the two continuous symmetries associated with the conservation of $N$ and ${\cal M}$ as in current experiments.