Adiabatic cooling of Fermions in an optical lattice

TL;DR

This paper calculates entropy-temperature relationships for non-interacting fermions in a 3D optical lattice to understand adiabatic cooling and heating effects, revealing regimes of temperature control and effects of lattice loading.

Contribution

It provides a detailed analysis of adiabatic cooling and heating regimes for fermions in optical lattices, including effects of band gaps and non-adiabatic loading.

Findings

Regimes where lattice loading cools or heats the fermions.

Disappearance of cooling regimes near band gaps.

Lattice loading can increase system degeneracy.

Abstract

The entropy-temperature curves are calculated for non-interacting fermions in a 3D optical lattice. These curves facilitate understanding of how adiabatic changes in the lattice depth affect the temperature, and we demonstrate regimes where the atomic sample can be significantly heated or cooled. When the Fermi energy of the system is near the location of a band gap the cooling regimes disappear for all temperatures and the system can only be heated by lattice loading. For samples with greater than one fermion per site we find that lattice loading can lead to a large increase in the degeneracy of the system. We study the scaling properties of the system in the degenerate regimes and assess the effects of non-adiabatic loading.