Entropy exchange in a mixture of ultracold atoms

TL;DR

This paper demonstrates experimental control of entropy transfer between two ultracold atomic gases using species-selective trapping, enabling the achievement of low entropies and temperature measurement in quantum systems.

Contribution

It introduces a novel method for controlling and transferring entropy between atomic gases, facilitating access to low-entropy quantum phases and improved temperature diagnostics.

Findings

Successful entropy transfer between two atomic species

Verification of thermalization in a 1D optical lattice

Potential applications in quantum phase realization and temperature measurement

Abstract

We investigate experimentally the entropy transfer between two distinguishable atomic quantum gases at ultralow temperatures. Exploiting a species-selective trapping potential, we are able to control the entropy of one target gas in presence of a second auxiliary gas. With this method, we drive the target gas into the degenerate regime in conditions of controlled temperature by transferring entropy to the auxiliary gas. We envision that our method could be useful both to achieve the low entropies required to realize new quantum phases and to measure the temperature of atoms in deep optical lattices. We verified the thermalization of the two species in a 1D lattice.