Many-body soliton-like states of the bosonic ideal gas

TL;DR

This paper investigates the lowest energy states of bosons on a ring, revealing that even non-interacting states exhibit soliton-like features due to bosonic symmetry, bridging mean field and many-body perspectives.

Contribution

It demonstrates that yrast states of non-interacting bosons display soliton characteristics, linking mean field solitons with many-body eigenstates through symmetry considerations.

Findings

Yrast states show phase jumps and density notches even without interactions.

Soliton features are due to bosonic symmetrization, not interactions.

Yrast states contain Dicke states encoding soliton-like properties.

Abstract

We study the lowest energy states for fixed total momentum, i.e. yrast states, of $N$ bosons moving on a ring. As in the paper of A. Syrwid and K. Sacha \cite{syrwid2015} , we compare mean field solitons with the yrast states, being the many-body Lieb-Liniger eigenstates. We show that even in the limit of vanishing interaction the yrast states possess features typical for solitons, like the phase jumps and the density notches. These properties are simply effects of the bosonic symmetrization and are encoded in the Dicke states hidden in the yrast states.