Resonant demagnetization of a dipolar BEC in a 3D optical lattice

TL;DR

This paper investigates dipolar relaxation resonances in a chromium BEC within a 3D optical lattice, revealing insights into band spectroscopy, on-site interactions, and entangled three-body states.

Contribution

It introduces a method to perform 3D band spectroscopy using dipolar relaxation resonances and demonstrates probing of number squeezing and entangled states in a Mott insulator.

Findings

Identification of dipolar relaxation resonances matching higher energy band excitations

Sensitivity of resonance line-shape to on-site interaction energy

Observation of three-body states with entangled spin and orbital degrees of freedom

Abstract

We study dipolar relaxation of a chromium BEC loaded into a 3D optical lattice. We observe dipolar relaxation resonances when the magnetic energy released during the inelastic collision matches an excitation towards higher energy bands. A spectroscopy of these resonances for two orientations of the magnetic field provides a 3D band spectroscopy of the lattice. The narrowest resonance is registered for the lowest excitation energy. Its line-shape is sensitive to the on-site interaction energy. We use such sensitivity to probe number squeezing in a Mott insulator, and we reveal the production of three-body states with entangled spin and orbital degrees of freedom.