title: Equation of State of Ultracold Fermions in the 2D BEC-BCS Crossover Region.
abstract: We report the experimental measurement of the equation of state of a two-dimensional Fermi gas with attractive s-wave interactions throughout the crossover from a weakly coupled Fermi gas to a Bose gas of tightly bound dimers as the interaction strength is varied. We demonstrate that interactions lead to a renormalization of the density of the Fermi gas by several orders of magnitude. We compare our data near the ground state and at finite temperature with predictions for both fermions and bosons from quantum Monte Carlo simulations and Luttinger-Ward theory. Our results serve as input for investigations of close-to-equilibrium dynamics and transport in the two-dimensional system.
authors.affiliation: Institute for Theoretical Physics, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Boettcher
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Bayha
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Kedar
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: P A
authors.initials: PA
authors.lastname: Murthy
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Neidig
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: M G
authors.initials: MG
authors.lastname: Ries
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: A N
authors.initials: AN
authors.lastname: Wenz
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Zürn
authors.affiliation: Physikalisches Institut, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Jochim
authors.affiliation: Institute for Theoretical Physics, Heidelberg University, D-69120 Heidelberg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Enss