High T c superfluidity in a quantum degenerate Fermi gas

Georgy V. Shlyapnikov

Mirta Rodríguez, Päivi Törmä

The possibility of Bloch oscillations for a degenerate and superfluid Fermi gas of atoms in an optical lattice is considered. For a one-component degenerate gas the oscillations are suppressed for high temperatures and band fillings. For a two-component gas, Landau criterion is used for specifying the regime where robust Bloch oscillations of the superfluid may be observed. We show how the amplitude of Bloch oscillations varies along the crossover from BCS to Bose-Einstein condensation.

Q. J. Chen, C.-C. Chien, Y. He +1 more

Murray Holland, S. J. J. M. F. Kokkelmans, M. L. Chiofalo +1 more

We consider the superfluid phase transition that arises when a Feshbach resonance pairing occurs in a dilute Fermi gas. We apply our theory to consider a specific resonance in potassium ((40)K), and find that for achievable experimental conditions, the transition to a superfluid phase is possible at the high critical temperature of about 0.5T(F). Observation of superfluidity in this regime would provide the opportunity to experimentally study the crossover from the superfluid phase of weakly coupled fermions to the Bose-Einstein condensation of strongly bound composite bosons.

Wolfgang Ketterle, Yong-il Shin, André Schirotzek +1 more

Christopher P. Search, Han Pu, W. Zhang +1 more

An atomic grating generated by a pulsed standing-wave laser field is proposed to manipulate the superfluid state in a quantum degenerate gas of fermionic atoms. We show that in the presence of atomic Cooper pairs, the density oscillations of the gas caused by the atomic grating exhibit a much longer coherence time than that in the normal Fermi gas. Our result indicates that the technique of a pulsed atomic grating is a potential candidate to detect the atomic superfluid state in a quantum degenerate Fermi gas.