Strong Correlations in the Dynamical Evolution of Lowest Landau Level Bosons

TL;DR

This paper explores the dynamical evolution of lowest Landau level bosons, revealing weakly-interacting clusters and slow thermalization indicative of quantum many-body scars, through exact diagonalization and semiclassical analysis.

Contribution

It introduces a novel understanding of cluster formation and slow thermalization in low-density bosonic systems beyond mean-field theory.

Findings

Observation of oscillations in observables due to few-body boundstates

Prediction of power-law growth of cloud width over time

Identification of slow thermalization as quantum many-body scars

Abstract

Recent experiments with rotating Bose gases have demonstrated the interaction-driven hydrodynamic instability of an initial extended strip-like state in the lowest Landau level. We investigate this phenomenon in the low density limit, where the mean-field Gross--Pitaevskii theory becomes inadequate, using exact diagonalisation studies and analytic arguments. We show that the behaviour can be understood in terms of weakly-interacting repulsively-bound few-body clusters. Signatures of cluster behaviour are observed in the expectation values of observables which oscillate at frequencies characterised by the energies of few-body boundstates. Using a semiclassical theory for interacting clusters, we predict the long-time growth of the cloud width to be a power law in the logarithm of time. This slow thermalisation of bound clusters represents a form of quantum many-body scars.