Generalized grand-canonical ensemble theory for interacting Bose-Einstein systems

TL;DR

This paper extends the grand-canonical ensemble theory for Bose-Einstein condensates by incorporating particle interactions, revealing a true phase transition and aligning better with experimental observations.

Contribution

It introduces a generalized theory using the maximum information principle to include interactions, explaining the nature of phase transitions in BECs.

Findings

Interacting BECs exhibit a real, abrupt phase transition.

The generalized theory aligns with experimental results.

Non-interacting models predict a smooth transition, unlike the interacting case.

Abstract

We use the maximum information principle to include particle-interaction into the grand-canonical theory of BECs. The inclusion of the particle-interaction elucidates why thermodynamic calculations for BECs by the grand-canonical ensemble for the non-interacting case are in coincidence with up to date experimental results. However, in our generalized theory we can show that a BEC experiences a real and abrupt phase-transition in contrast to the smooth phase-transition predicted by the non-interacting grand-canonical ensemble. In addition, we discuss possible effects due to a thermal environment and the experimental probing from a general point of view.