Observation of photon-assisted tunneling in optical lattices

TL;DR

This paper reports the experimental observation of photon-assisted tunneling in Bose-Einstein condensates within optical lattices, demonstrating control over tunneling suppression and enhancement via external forces and shaking.

Contribution

It provides the first experimental demonstration of photon-assisted tunneling in optical lattices, aligning with theoretical models and showcasing optical lattices as platforms for solid-state physics studies.

Findings

Tunneling can be suppressed by a large constant force.

Photon-assisted tunneling resumes when sinusoidal shaking is applied.

Results agree with theoretical predictions.

Abstract

We have observed tunneling suppression and photon-assisted tunneling of Bose-Einstein condensates in an optical lattice subjected to a constant force plus a sinusoidal shaking. For a sufficiently large constant force, the ground energy levels of the lattice are shifted out of resonance and tunneling is suppressed; when the shaking is switched on, the levels are coupled by low-frequency photons and tunneling resumes. Our results agree well with theoretical predictions and demonstrate the usefulness of optical lattices for studying solid-state phenomena.