Universal Thermodynamic and Spin Transport Properties of Strongly Interacting Fermi Gases

POSTER

Abstract

We perform a high-precision measurement of the equation of state of a Fermi gas with unitarity limited interactions by in- situ imaging of ultracold $^6$Li at a Feshbach resonance. We observe the superfluid phase transition in the chemical potential, entropy, compressibility and heat capacity, and provide a new value of the Bertsch parameter $\xi_S$. In a separate set of measurements, we determine the spin transport properties of strongly interacting Fermi gases by spatially separating the two spin components and allowing the system to relax to equilibrium (arXiv:1101.0780v1). We find that the spin diffusivity approaches a universal minimum value set by the ratio of Planck's constant to the atomic mass, and determine the spin susceptibility from spin transport properties.

*This work was supported by the NSF, AFOSR-MURI, ARO-MURI, ONR, DARPA YFA, a grant from the Army Research Office with funding from the DARPA OLE program, the David and Lucille Packard Foundation and the Alfred P. Sloan Foundation.

Authors

  • Ariel Sommer

    • Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA

  • Mark Ku

    • Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA

  • Lawrence Cheuk

    • Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA
    • Princeton University

  • Martin Zwierlein

    • Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA