Adiabatic Loading of Cold Bosons in Three-Dimensional Optical Lattices and Superfluid-Normal Phase Transition

TL;DR

This paper studies how adiabatic loading affects temperature changes in cold bosons within 3D optical lattices, revealing phase-dependent cooling and heating behaviors near the superfluid-normal transition.

Contribution

It provides a mean-field analysis of temperature evolution during adiabatic lattice loading, highlighting phase-specific thermal responses and their dependence on lattice height and initial temperature.

Findings

Cooling occurs in superfluid phase during adiabatic loading.

Heating occurs in normal phase during adiabatic loading.

Efficiency of thermal change increases at higher initial temperatures.

Abstract

We investigate the effects of the adiabatic loading of optical lattices to the temperature by applying the mean-field approximation to the three-dimensional Bose-Hubbard model at finite temperatures. We compute the lattice-height dependence of the isentropic curves for the given initial temperatures in case of the homogeneous system i.e., neglecting the trapping potential. Taking the unit of temperatures as the recoil energy, the adiabatic cooling/heating through superfluid (SF) - normal (N) phase transition is clearly understood. It is found that the cooling occurs in SF phase while the heating occurs in N phase and the efficiency of adibatic cooling/heating is higher at higher temperatures. We also explain how its behavior can be understood from the lattice-hight dependence of dispersion relation in each phase. Furthermore, the connection of the adiabatic heating/cooling between the cases with/without the trapping potential is discussed.