Interaction-induced directional transport on periodically driven chains

TL;DR

This paper investigates how interactions in a periodically driven chain system induce directional transport, with particles forming bound states called doublons that move directionally depending on initial conditions.

Contribution

It introduces a model where interactions cause coupled particle movement and directional transport, highlighting the role of energy separation and initial configurations.

Findings

Interaction causes formation of bound doublons.

Doublon movement direction depends on initial configuration.

Periodic driving enables controlled directional transport.

Abstract

We study a driven system in which interaction between particles causes their directional, coupled movement. In that model system, two particles move alternatingly in time on two coupled chains. Without interaction, both particles diffuse along their respective chains, independent from one another. Interaction between them, no matter if attractive or repellent, leads to an energetic separation of configurations where the particles are close to each other and those where they are farther separated. The energy difference causes close-by particles to remain bound together, forming a doublon. Their relative position in the starting configuration determines whether the doublon moves to the left or right or remains stationary due to the periodic driving.