Quantum phase diffusion of a Bose system: beyond the Hartree-Fock-Bogoliubov approximation

TL;DR

This paper extends the Hartree-Fock-Bogoliubov approach to better understand phase diffusion in finite-size Bose systems, surpassing the limitations of the traditional Bogoliubov approximation.

Contribution

It introduces a generalized Hartree-Fock-Bogoliubov method that accurately describes phase diffusion beyond the standard approximation.

Findings

Recovering phase diffusion with the generalized approach

Limitations of the Bogoliubov approximation addressed

Enhanced theoretical understanding of Bose system phase dynamics

Abstract

A diffusion process is usually assumed for the phase of the order parameter of a Bose system of finite size. The theoretical basis is limited to the so called Bogoliubov approximation. We show that a suitable generalization of the Hartree-Fock-Bogoliubov approach recovers phase diffusion.