Thermometry of Fermionic Atoms in an Optical Lattice

TL;DR

This paper presents a method to measure the temperature of fermionic atoms in optical lattices by analyzing the fraction of doubly occupied sites, enabling precise thermometry crucial for studying quantum phases.

Contribution

It introduces an analytical approach to determine the temperature-dependent double occupancy and proposes using Feshbach resonance for accurate thermometry in optical lattices.

Findings

Double occupancy fraction strongly depends on temperature.

Analytical calculation matches numerical simulations.

Feshbach resonance enables precise thermometry.

Abstract

Low temperatures are necessary for the observation of strongly correlated quantum phases of fermionic atoms in optical lattices. We analyze how the temperature of a Fermi gas is altered when the fermions are loaded into an optical lattice with an underlying harmonic confining potential and show how the temperature can be measured. The temperature of the atoms in the optical lattice determines the fraction of doubly occupied lattice sites of a two-component Fermi gas. We analytically calculate this quantity and find a strong temperature dependence. This fraction can be measured by studying the production of molecules in the lattice using a Feshbach resonance which allows for precise thermometry of atoms in an optical lattice.