Bosonic molecules in rotating traps

TL;DR

This paper introduces a variational wave function for rotating bosons that captures correlations beyond mean-field theory, revealing crystalline patterns and lower energies than traditional approaches in certain regimes.

Contribution

It develops a new variational wave function for rotating bosons that describes localized crystalline structures and includes correlations beyond the Gross-Pitaevskii mean field.

Findings

RBMs form polygonal-ring-like patterns.

RBM energies are lower than GP solutions for small boson numbers.

Ground-state angular momenta show periodic dependence on boson number.

Abstract

We present a variational many-body wave function for repelling bosons in rotating traps, focusing on rotational frequencies that do not lead to restriction to the lowest Landau level. This wave function incorporates correlations beyond the Gross-Pitaevskii (GP) mean field approximation, and it describes rotating boson molecules (RBMs) made of localized bosons that form polygonal-ring-like crystalline patterns in their intrinsic frame of reference. The RBMs exhibit characteristic periodic dependencies of the ground-state angular momenta on the number of bosons in the polygonal rings. For small numbers of neutral bosons, the RBM ground-state energies are found to be always lower than those of the corresponding GP solutions, in particular in the regime of GP vortex formation.