Induced correlations between impurities in a one-dimensional quenched Bose gas

TL;DR

This paper investigates how two impurities in a one-dimensional Bose gas interact and evolve after a sudden change in their interaction strength, revealing insights into impurity correlations through numerical simulations.

Contribution

It introduces a variational multilayer multiconfiguration time-dependent Hartree method for bosons to study impurity dynamics and proposes an effective two-body Hamiltonian to explain weak interaction behaviors.

Findings

Impurity-impurity correlations are induced and evolve during the quench.

The effective two-body model captures qualitative features of the dynamics for weak interactions.

Quench dynamics can serve as a tool to study impurity correlations in cold-atom systems.

Abstract

We explore the time evolution of two impurities in a trapped one-dimensional Bose gas that follows a change of the boson-impurity interaction. We study the induced impurity-impurity interactions and their effect on the quench dynamics. In particular, we report on the size of the impurity cloud, the impurity-impurity entanglement, and the impurity-impurity correlation function. The presented numerical simulations are based upon the variational multilayer multiconfiguration time-dependent Hartree method for bosons. To analyze and quantify induced impurity-impurity correlations, we employ an effective two-body Hamiltonian with a contact interaction. We show that the effective model consistent with the mean-field attraction of two heavy impurities explains qualitatively our results for weak interactions. Our findings suggest that the quench dynamics in cold-atom systems can be a tool for studying impurity-impurity correlations.