Phase Separation in Bose-Superfluid Fermi Mixtures

Tilman Enss, W. Zwerger

J. M. J. van Leeuwen, E. G. D. Cohen

Linghua Wen, Jinghong Li

We investigate the structure and dynamics of a rotating superfluid Bose-Fermi mixture (SBFM) made of superfluid bosons and two-component (spin-up and -down) superfluid fermions. A ground-state phase diagram for the nonrotating case of a SBFM with specific parameters is given, where the ground-state configuration of a nonrotating SBFM is mainly determined by the boson-fermion interaction. For the rotating case of a SBFM with a sufficiently large rotation frequency, we show that the system supports a mixed phase and three typical layer-separated phases. In particular, the visible vortex formation in the fermionic superfluid exhibits a remarkable hysteresis effect during the dynamical evolution of a rotating SBFM, which is evidently different from the case of rotating two-component Bose-Einstein condensates.

S. G. Bhongale, Han Pu

We study the phase diagram of the mixture of a Bose-Einstein condensate and a two-component Fermi gas. In particular, we identify the regime where the homogeneous system becomes unstable against phase separation. We show that, under proper conditions, the phase-separation phenomenon can be exploited as a robust probe of ``local'' Fermi superfluidity.

Sébastien Laurent, Marion Delehaye, Shu‐Wei Jin +4 more

M. Iskin, C. A. R. Sá de Melo

The ground state phase diagram of fermion mixtures in optical lattices is analyzed as a function of interaction strength, fermion filling factor, and tunneling parameters. In addition to standard superfluid, phase-separated or coexisting superfluid -- excess-fermion phases found in homogeneous or harmonically trapped systems, fermions in optical lattices have several insulating phases, including a molecular Bose-Mott insulator (BMI), a Fermi-Pauli (band) insulator (FPI), a phase-separated BMI-FPI mixture or a Bose-Fermi checkerboard (BFC). The molecular BMI phase is the fermion mixture counterpart of the atomic BMI found in atomic Bose systems, the BFC or BMI-FPI phases exist in Bose-Fermi mixtures, and lastly the FPI phase is particular to the Fermi nature of the constituent atoms of the mixture.