An accordion superlattice for controlling atom separation in optical potentials

TL;DR

This paper introduces an 'accordion superlattice' technique that enables controllable, large-distance separation of atoms in optical lattices through cyclic transfer between variable-spacing lattices, with potential applications in quantum computing and biological systems.

Contribution

The paper presents a novel method for atom separation in optical lattices using cyclic transfer between variable-spacing lattices, demonstrated through simulations and a proof-of-principle experiment.

Findings

Atoms remain localized during separation process

Numerical simulations show effective large-distance separation

Proof-of-principle experiment demonstrates optical fields for the method

Abstract

We propose a method for separating trapped atoms in optical lattices by large distances. The key idea is the cyclic transfer of atoms between two lattices of variable spacing, known as accordion lattices, each covering at least a factor of two in lattice spacing. By coherently loading atoms between the two superimposed potentials, we can reach, in principle, arbitrarily large atom separations, while requiring only a relatively small numerical aperture. Numerical simulations of our `accordion superlattice' show that the atoms remain localised to one lattice site throughout the separation process, even for moderate lattice depths. In a proof-of-principle experiment we demonstrate the optical fields required for the accordion superlattice using acousto-optic deflectors. The method can be applied to neutral-atom quantum computing with optical tweezers, as well as quantum simulation of low-entropy many-body states. For instance, a unit-filling atomic Mott insulator can be coherently expanded by a factor of ten in order to load an optical tweezer array with very high filling. In turn, sorted tweezer arrays can be compressed to form high-density states of ultracold atoms in optical lattices. The method can be also be applied to biological systems where dynamical separation of particles is required.