Adiabatic cooling of a tunable Bose-Fermi mixture in an optical lattice

TL;DR

This paper investigates the thermodynamics of a tunable Bose-Fermi mixture in an optical lattice, showing how adiabatic magnetic field ramps can reduce system temperature by adjusting particle composition.

Contribution

It provides a detailed analysis of the entropy and temperature behavior during adiabatic ramps across a Feshbach resonance in a lattice-confined atomic gas.

Findings

Adiabatic ramps can lower temperature by tuning particle ratios.

Optimal filling fractions enhance cooling effects.

System behavior depends on lattice and atom-molecule interactions.

Abstract

We consider an atomic Fermi gas confined in a uniform optical lattice potential, where the atoms can pair into molecules via a magnetic field controlled narrow Feshbach resonance. Thus by adjusting the magnetic field the portion of fermionic and bosonic particles in the system can be continuously varied. We analyze the statistical mechanics of this system and consider the interplay of the lattice physics with the atom-molecule conversion. We study the entropic behavior of the system and characterize the temperature changes that occur during adiabatic ramps across the Feshbach resonance. We show that an appropriate choice of filling fraction can be used to reduce the system temperature during such ramps.