Many-body quantum dynamics and induced correlations of Bose polarons

TL;DR

This paper investigates the ground state and nonequilibrium dynamics of two spinor bosonic impurities in a 1D bosonic gas, revealing induced interactions, impurity correlations, and polaron behavior through quench experiments.

Contribution

It provides new insights into impurity interactions, correlation patterns, and dynamical properties of Bose polarons in one-dimensional systems.

Findings

Signatures of attractive induced interactions in the ground state.

Impurities exhibit superposition of configurations after a quench.

Strong attractions lead to impurity localization and density humps in the bath.

Abstract

We study the ground state properties and nonequilibrium dynamics of two spinor bosonic impurities immersed in a one-dimensional bosonic gas upon applying an interspecies interaction quench. For the ground state of two non-interacting impurities we reveal signatures of attractive induced interactions in both cases of attractive or repulsive interspecies interactions, while a weak impurity-impurity repulsion forces the impurities to stay apart. Turning to the quench dynamics we inspect the time-evolution of the contrast unveiling the existence, dynamical deformation and the orthogonality catastrophe of Bose polarons. We find that for an increasing postquench repulsion the impurities reside in a superposition of two distinct two-body configurations while at strong repulsions their corresponding two-body correlation patterns show a spatially delocalized behavior evincing the involvement of higher excited states. For attractive interspecies couplings, the impurities exhibit a tendency to localize at the origin and remarkably for strong attractions they experience a mutual attraction on the two-body level that is imprinted as a density hump on the bosonic bath.