Interaction-controlled impurity transport in trapped mixtures of ultracold bosons

TL;DR

This paper presents a method for controlling impurity transport in ultracold bosonic mixtures by dynamically tuning interactions, demonstrating effective impurity pinning and storage with correlation effects stabilizing the process.

Contribution

It introduces a protocol using linear ramps of interaction strengths to control impurity transfer in a double-well ultracold mixture, accounting for correlations with advanced simulation methods.

Findings

Efficient impurity pinning and unpinning via interaction ramps.

Inter-species correlations stabilize impurity transport.

Majority components remain self-trapped during the process.

Abstract

We explore the dynamical transport of an impurity between different embedding majority species which are spatially separated in a double well. The transfer and storage of the impurity is triggered by dynamically changing the interaction strengths between the impurity and the two majority species. We find a simple but efficient protocol consisting of linear ramps of majority-impurity interactions at designated times to pin or unpin the impurity. Our study of this highly imbalanced few-body triple mixture is conducted with the multi-layer multi-configuration time-dependent Hartree method for atomic mixtures which accounts for all interaction-induced correlations. We analyze the dynamics in terms of single-particle densities, entanglement growth and provide an effective potential description involving mean-fields of the interacting components. The majority components remain self-trapped in their individual wells at all times, which is a crucial element for the effectiveness of our protocol. During storage times each component performs low-amplitude dipole oscillations in a single well. Unexpectedly, the inter-species correlations possess a stabilizing impact on the transport and storage properties of the impurity particle.