Thermal versus Quantum Fluctuations of Optical Lattice Fermions

TL;DR

This paper investigates how fermionic atoms in a 1D optical lattice exhibit a non-monotonic relationship between temperature and double occupancy, revealing a potential cooling mechanism and a signature of quantum fluctuations.

Contribution

It demonstrates the persistence of non-monotonic double occupancy behavior under realistic conditions and links it to quantum fluctuation signatures and cooling strategies.

Findings

Double occupancy is non-monotonic with temperature.

Intermediate temperatures suppress entropy, enabling cooling.

Quantum fluctuations dominate at specific temperature ranges.

Abstract

We show that, for fermionic atoms in a one-dimensional optical lattice, the fraction of atoms in doubly occupied sites is a highly non-monotonic function of temperature. We demonstrate that this property persists even in the presence of realistic harmonic confinement, and that it leads to a suppression of entropy at intermediate temperatures that offers a route to adiabatic cooling. Our interpretation of the suppression is that such intermediate temperatures are simultaneously too high for quantum coherence and too low for significant thermal excitation of double occupancy thus offering a clear indicator of the onset of quantum fluctuations.