Dynamical symmetry and pair tunneling in a one-dimensional Bose gas colliding with a mobile impurity

TL;DR

This paper uses TDMRG to analyze how a 1D Bose gas interacts with a mobile impurity, revealing sign-independent dynamics and resonant pair tunneling at specific interaction energies, with implications for ultracold atom experiments.

Contribution

It demonstrates the approximate sign-independence of impurity-boson interactions and identifies resonant pair tunneling phenomena in a 1D Bose gas with an impurity.

Findings

Sign-independence of impurity-boson interaction effects.

Resonant pair tunneling at specific interaction energies.

Predictions testable with ultracold atom experiments.

Abstract

Using the time-dependent density matrix renormalization group (TDMRG) we theoretically study the collision of a one-dimensional gas of interacting bosons with an impurity trapped in a shallow box potential. We study the dynamic response of both the impurity and the bosonic gas and find an approximate independence of the sign of the interaction (attractive or repulsive) between the impurity and the bosons. This sign-independence breaks down when the interaction energy is of the same order as the box potential depth, leading to resonant pair tunneling. Our predictions can be tested using contemporary techniques with ultracold atoms.