Material-barrier Tunneling in One-dimensional Few-boson Mixtures

TL;DR

This paper investigates the quantum dynamics of strongly interacting one-dimensional bosonic mixtures, revealing how a localized species acts as a barrier and influences tunneling and correlated states, with implications for understanding few-body quantum systems.

Contribution

It introduces a detailed analysis of how a localized species in a bosonic mixture acts as an effective barrier and affects inter-species dynamics, including induced attractions and correlated states.

Findings

Localized species can serve as an effective potential barrier.

Backaction induces attraction that can dominate intra-species interactions.

Backaction significantly alters tunneling dynamics of bound pairs.

Abstract

We study the quantum dynamics of strongly interacting few-boson mixtures in one-dimensional traps. If one species is strongly localized compared to the other (e.g., much heavier), it can serve as an effective potential barrier for that mobile component. Near the limit of infinite localization, we map this to a system of identical bosons in a double well. For realistic localization, the backaction of the light species on the "barrier" atoms is explained--to lowest order--in terms of an induced attraction between these. Even in equilibrium, this may outweigh the bare intra-species interaction, leading to unexpected correlated states. Remarkably, the backaction drastically affects the inter-species dynamics, such as the tunneling of an attractively bound pair of fermionized atoms.