Coexistence of pairing gaps in three-component Fermi gases

We study a three-component superfluid Fermi gas in a spherically symmetric harmonic trap using the Bogoliubov-deGennes method. We predict a coexistence phase in which two pairing field order parameters are simultaneously nonzero, in stark contrast to studies performed for trapped gases using local density approximation. We also discuss the role of atom number conservation in the context of a homogeneous system.Comment: Text revised, added two figures and three reference

Optical response of superfluid state in dilute atomic Fermi-Dirac gases

We theoretically study the propagation of light in a Fermi-Dirac gas in the presence of a superfluid state. BCS pairing between atoms in different hyperfine levels may significantly increase the optical linewidth and line shift of a quantum degenerate Fermi-Dirac gas and introduce a local-field correction that, under certain conditions, dramatically dominates over the Lorentz-Lorenz shift. These optical properties could possibly unambiguously sign the presence of the superfluid state and determine the value of the BCS order parameter.Comment: 5 pages, 2 figure

Optical linewidth of a low density Fermi-Dirac gas

We study propagation of light in a Fermi-Dirac gas at zero temperature. We analytically obtain the leading density correction to the optical linewidth. This correction is a direct consequence of the quantum statistical correlations of atomic positions that modify the optical interactions between the atoms at small interatomic separations. The gas exhibits a dramatic line narrowing already at very low densities.Comment: 4 pages, 2 figure

Exploring a quantum degenerate gas of fermionic atoms

We predict novel phenomena in the behavior of an ultra- cold, trapped gas of fermionic atoms. We find that quantum statistics radically changes the collisional properties, spatial profile, and off-resonant light scattering properties of the atomic fermion system, and we suggest how these effects can be observed.Comment: 5 pages, 3 figure

Scattering of short laser pulses from trapped fermions

We investigate the scattering of intense short laser pulses off trapped cold fermionic atoms. We discuss the sensitivity of the scattered light to the quantum statistics of the atoms. The temperature dependence of the scattered light spectrum is calculated. Comparisons are made with a system of classical atoms who obey Maxwell-Boltzmann statistics. We find the total scattering increases as the fermions become cooler but eventually tails off at very low temperatures (far below the Fermi temperature). At these low temperatures the fermionic degeneracy plays an important role in the scattering as it inhibits spontaneous emission into occupied energy levels below the Fermi surface. We demonstrate temperature dependent qualitative changes in the differential and total spectrum can be utilized to probe quantum degeneracy of trapped Fermi gas when the total number of atoms are sufficiently large $(\geq 10^6)$. At smaller number of atoms, incoherent scattering dominates and it displays weak temperature dependence.Comment: updated figures and revised content, submitted to Phys.Rev.

Observation of p-wave Threshold Law Using Evaporatively Cooled Fermionic Atoms

We have measured independently both s-wave and p-wave cross-dimensional thermalization rates for ultracold potassium-40 atoms held in a magnetic trap. These measurements reveal that this fermionic isotope has a large positive s-wave triplet scattering length in addition to a low temperature p-wave shape resonance. We have observed directly the p-wave threshold law which, combined with the Fermi statistics, dramatically suppresses elastic collision rates at low temperatures. In addition, we present initial evaporative cooling results that make possible these collision measurements and are a precursor to achieving quantum degeneracy in this neutral, low-density Fermi system.Comment: 5 pages, 3 figures, 1 tabl