Dark state cooling of atoms by superfluid immersion

TL;DR

This paper introduces a novel cooling scheme for atoms in optical lattices using superfluid immersion, achieving ultra-low temperatures by replacing electronic states with motional levels and phonon emission with spontaneous emission into a Bose-Einstein condensate.

Contribution

It presents a new dark state cooling method that leverages superfluid phonon emission to cool atoms to sub-Bloch band temperatures, extending laser cooling concepts.

Findings

Achieves temperatures much lower than the reservoir temperature.

Provides a theoretical framework for superfluid-immersed atom cooling.

Demonstrates potential for ultra-cold atom preparation in optical lattices.

Abstract

We propose and analyse a scheme to cool atoms in an optical lattice to ultra-low temperatures within a Bloch band, and away from commensurate filling. The protocol is inspired by ideas from dark state laser cooling, but replaces electronic states with motional levels, and spontaneous emission of photons by emission of phonons into a Bose-Einstein condensate, in which the lattice is immersed. In our model, achievable temperatures correspond to a small fraction of the Bloch band width, and are much lower than the reservoir temperature.