title: Entropy exchange in a mixture of ultracold atoms.
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.
authors.affiliation: LENS-European Laboratory for Non-Linear Spectroscopy and Dipartimento di Fisica, Università di Firenze, via N. Carrara 1, I-50019 Sesto Fiorentino-Firenze, Italy.
authors.forename: J
authors.initials: J
authors.lastname: Catani
authors.forename: G
authors.initials: G
authors.lastname: Barontini
authors.forename: G
authors.initials: G
authors.lastname: Lamporesi
authors.forename: F
authors.initials: F
authors.lastname: Rabatti
authors.forename: G
authors.initials: G
authors.lastname: Thalhammer
authors.forename: F
authors.initials: F
authors.lastname: Minardi
authors.forename: S
authors.initials: S
authors.lastname: Stringari
authors.forename: M
authors.initials: M
authors.lastname: Inguscio