Bloch Oscillations Along a Synthetic Dimension of Atomic Trap States

TL;DR

This paper demonstrates the first experimental realization of a long, controllable synthetic dimension using atomic trap states, enabling observation of Bloch oscillations and opening pathways for exploring higher-dimensional topological physics.

Contribution

It introduces a novel method to create and control a synthetic dimension of atomic trap states via dynamic modulation, allowing detailed study of Bloch oscillations in this system.

Findings

Observation of Bloch oscillations in atomic trap states

Control over the synthetic dimension through modulation parameters

Agreement between experimental results, simulations, and theory

Abstract

Synthetic dimensions provide a powerful approach for simulating condensed matter physics in cold atoms and photonics, whereby a set of discrete degrees of freedom are coupled together and re-interpreted as lattice sites along an artificial spatial dimension. However, atomic experimental realisations have been limited so far by the number of artificial lattice sites that can be feasibly coupled along the synthetic dimension. Here, we experimentally realise for the first time a very long and controllable synthetic dimension of atomic harmonic trap states. To create this, we couple trap states by dynamically modulating the trapping potential of the atomic cloud with patterned light. By controlling the detuning between the frequency of the driving potential and the trapping frequency, we implement a controllable force in the synthetic dimension. This induces Bloch oscillations in which atoms move periodically up and down tens of atomic trap states. We experimentally observe the key characteristics of this behaviour in the real space dynamics of the cloud, and verify our observations with numerical simulations and semiclassical theory. This experiment provides an intuitive approach for the manipulation and control of highly-excited trap states, and sets the stage for the future exploration of topological physics in higher dimensions.