Light scattering for thermometry of fermionic atoms in an optical lattice

TL;DR

This paper introduces a novel optical method to measure the temperature of fermionic atoms in an optical lattice by analyzing fluctuations in the far-field diffraction pattern of scattered light, with enhanced sensitivity from harmonic trapping.

Contribution

It presents a new thermometry technique based on light scattering that accurately detects thermal correlations in fermionic atom lattices, improving temperature measurement precision.

Findings

Thermal correlations cause detectable fluctuations in scattered light intensity.

The method can distinguish temperature variations above shot noise levels.

Harmonic trapping enhances measurement sensitivity.

Abstract

We propose a method for measuring the temperature of fermionic atoms in an optical lattice potential from the intensity of the scattered light in the far-field diffraction pattern. We consider a single-component gas in a tightly-confined two-dimensional lattice, illuminated by far off-resonant light driving a cycling transition. Our calculations show that thermal correlations of the fermionic atoms generate fluctuations in the intensity of the diffraction pattern of light scattered from the atomic lattice array and that this signal can be accurately detected above the shot noise using a lens to collect photons scattered in a forward direction (with the diffraction maxima blocked). The sensitivity of the thermometer is enhanced by an additional harmonic trapping potential.