Getting into Shape: Efficient Cooling Scheme for Fermionic Atoms in Optical Lattices

TL;DR

This paper introduces a practical method to cool fermionic atoms in optical lattices by spatially separating high-entropy regions, significantly reducing entropy and enabling access to quantum phases like antiferromagnetism.

Contribution

It presents a novel, experimentally feasible scheme for entropy reduction in fermionic optical lattices through potential shaping and atom isolation.

Findings

Entropy per particle can be reduced by a factor of 10.

Achieves entropy levels below 0.2 k_B per particle.

Procedure is robust against experimental variations.

Abstract

We propose an experimental procedure to cool fermionic atoms loaded into an optical lattice. The central idea is to spatially divide the system into entropy-rich and -poor regions by shaping the confining potential profile. Atoms in regions of high entropy per particle are subsequently isolated from the system. We discuss how to experimentally carry out this proposal, and perform a quantitative study of its efficiency. We find that the entropy per particle, $s$, can typically be reduced by a factor of 10 such that entropies lower than $s/k_B \sim 0.2$ can be reached. Cooling into highly sought-after quantum phases (such as an antiferromagnet) can thus be achieved. We show that this procedure is robust against variations of the experimental conditions.