We present theoretical findings on the spin collective modes of a two-species Fermi liquid, prepared alternatively in a polarized equilibrium or a polarized nonequilibrium state. We explore the effects on these modes of a diverging $s$ -wave scattering length, as occurs near a Feshbach resonance in a fermionic atomic gas. We compare these atomic gas modes with those of the conventional $^{3}\mathrm{He}$ system, and we find that they differ from the conventional systems, and that the gap and spin stiffness are tunable via the Feshbach resonance.We present theoretical findings on the spin collective modes of a two-species Fermi liquid, prepared alternatively in a polarized equilibrium or a polarized nonequilibrium state. We explore the effects on these modes of a diverging $s$-wave scattering length, as occurs near a Feshbach resonance in a fermionic atomic gas. We compare these atomic gas modes with those of the conventional $^{3}\mathrm{He}$ system, and we find that they differ from the conventional systems, and that the gap and spin stiffness are tunable via the Feshbach resonance.

arXiv:0807.0018Physical Review ASep 3, 20083 citations

AN ATOMIC FERMI GAS NEAR A P-WAVE FESHBACH RESONANCE

D. S. Jin, John Gaebler, John T. Stewart

Laser SpectroscopyApr 1, 20081 citation

Atomic Fermi gases at Feshbach resonance

G. M. Falco

APSMar 1, 20040 citations

Measurement of Sound Velocity in a Fermi Gas near a Feshbach Resonance

J. Joseph, Bason E. Clancy, Le Luo +3 more

Sound waves are excited in an optically trapped degenerate Fermi gas of spin-up and spin-down atoms with magnetically tunable interactions. Measurements are made throughout the crossover region, from a weakly interacting Fermi gas through the resonant Fermi superfluid regime to a Bose condensate of dimer molecules. The measured sound velocities test theories of hydrodynamic wave propagation and predictions of the equation of state. At resonance, the sound velocity exhibits universal scaling with the Fermi velocity, to within 1.8% over a factor of 30 in density.Sound waves are excited in an optically trapped degenerate Fermi gas of spin-up and spin-down atoms with magnetically tunable interactions. Measurements are made throughout the crossover region, from a weakly interacting Fermi gas through the resonant Fermi superfluid regime to a Bose condensate of dimer molecules. The measured sound velocities test theories of hydrodynamic wave propagation and predictions of the equation of state. At resonance, the sound velocity exhibits universal scaling with the Fermi velocity, to within 1.8% over a factor of 30 in density.

Physical Review LettersApr 24, 2007177 citations

s

-wave scattering length, as occurs near a Feshbach resonance in a fermionic atomic gas. We compare these atomic gas modes with those of the conventional

^{3}\mathrm{He}

system, and we find that they differ from the conventional systems, and that the gap and spin stiffness are tunable via the Feshbach resonance.