Observation of density-dependent gauge fields in a Bose-Einstein condensate based on micromotion control in a shaken two-dimensional lattice

TL;DR

This paper reports the experimental creation of a density-dependent gauge field in a Bose-Einstein condensate by synchronizing lattice shaking and interaction modulation, enabling control over quantum states via micromotion.

Contribution

It introduces a novel method to generate interaction-induced gauge fields in quantum gases through micromotion control in a shaken optical lattice.

Findings

Successful creation of a density-dependent gauge field in BECs.

Demonstration of control over quasimomentum states via modulation phase.

Establishment of a new platform for exploring quantum phenomena.

Abstract

We demonstrate a density-dependent gauge field, induced by atomic interactions, for quantum gases. The gauge field results from the synchronous coupling between the interactions and micromotion of the atoms in a modulated two-dimensional optical lattice. As a first step, we show that a coherent shaking of the lattice in two directions can couple the momentum and interactions of atoms and break the four-fold symmetry of the lattice. We then create a full interaction-induced gauge field by modulating the interaction strength in synchrony with the lattice shaking. When a condensate is loaded into this shaken lattice, the gauge field acts to preferentially prepare the system in different quasimomentum ground states depending on the modulation phase. We envision that these interaction-induced fields, created by fine control of micromotion, will provide a stepping stone to model new quantum phenomena within and beyond condensed matter physics.