Transport of atoms in a quantum conveyor belt

TL;DR

This paper experimentally investigates atom transport in a 3D Bose-Einstein condensate within a 1D optical lattice, revealing unusual band-structure properties and different behaviors based on initial quasimomentum states.

Contribution

It provides new insights into atom dynamics in moving and accelerating lattices, especially for states with large quasimomentum spread, and compares bosonic and fermionic behaviors.

Findings

Non-intuitive behavior of condensate in a moving lattice

Distinct dynamics for atoms with large quasimomentum spread

Comparison between bosonic and fermionic atom transport

Abstract

We have performed experiments using a 3D-Bose-Einstein condensate of sodium atoms in a 1D optical lattice to explore some unusual properties of band-structure. In particular, we investigate the loading of a condensate into a moving lattice and find non-intuitive behavior. We also revisit the behavior of atoms, prepared in a single quasimomentum state, in an accelerating lattice. We generalize this study to a cloud whose atoms have a large quasimomentum spread, and show that the cloud behaves differently from atoms in a single Bloch state. Finally, we compare our findings with recent experiments performed with fermions in an optical lattice.