On-top fragmentation stabilizes atom-rich attractive Bose-Einstein condensates

TL;DR

This paper demonstrates that atom-rich attractive Bose-Einstein condensates can form stable, fragmented metastable states beyond the critical atom number predicted by traditional theory, with analytical and numerical support.

Contribution

It reveals the existence of stable, fragmented metastable states in attractive BECs at atom numbers exceeding previous critical limits, expanding understanding of condensate stability.

Findings

Fragmented metastable states exist above the Gross-Pitaevskii critical atom number.

Fragments are strongly overlapping in space.

Results are supported analytically and numerically.

Abstract

It is well known that attractive condensates do not posses a stable ground state in three dimensions. The widely used Gross-Pitaevskii theory predicts the existence of metastable states up to some critical number $N_{\mathrm{cr}}^{\mathrm{GP}}$ of atoms. It is demonstrated here that fragmented metastable states exist for atom numbers well above $N_{\mathrm{cr}}^{\mathrm{GP}}$. The fragments are strongly overlapping in space. The results are obtained and analyzed analytically as well as numerically. The implications are discussed.