Persistent currents in Bose-Bose mixtures after an interspecies interaction quench

TL;DR

This paper investigates how a sudden increase in interspecies interactions affects persistent currents and entanglement in a two-component Bose gas in a ring lattice, revealing a quadratic relationship between current reduction and initial visibility.

Contribution

It demonstrates the impact of a strong interaction quench on persistent currents and entanglement in a Bose-Bose mixture, with specific scaling laws and independence from initial phases.

Findings

Current of gas B decreases after the quench.

Relative current decrease scales quadratically with gas A's visibility.

Entanglement entropy scales linearly with system size and relates to current reduction.

Abstract

We study the persistent currents and interspecies entanglement generation in a Bose-Bose mixture formed by two atomic gases (hereafter labelled by the letters A and B) trapped in a one-dimensional ring lattice potential with an artificial gauge field after a sudden quench from zero to strong interactions between the two gases. Assuming that the strength of these interactions is much larger than the single species energies and that the gas A is initially in the Mott-insulator regime, we show that the current of the gas B is reduced with respect to its value prior the interaction quench. Averaging fast oscillations out, the relative decrease of this current is independent of the initial visibility and Peierls phase of the gas B and behaves quadratically with the visibility of the gas A. The second R\'enyi entropy of the reduced state measuring the amount of entanglement between the two gases is found to scale linearly with the number of sites and to be proportional to the relative decrease of the current.