TY - GEN

T1 - Superfluid properties of an ultracold Fermi gas in the BCS-BEC crossover region

AU - Ohashi, Yoji

AU - Fukushima, Naoki

PY - 2009

Y1 - 2009

N2 - We investigate superfluid properties of a two-component Fermi gas in the BCS-BEC crossover region. Including strong-coupling effects within a Gaussian fluctuation approximation, we self-consistently determine the superfluid order parameter and chemical potential at finite temperatures. Using these self-consistent solutions, we calculate single-particle excitations, as well as collective mode, over the entire BCS-BEC crossover region. As one increases the strength of a pairing interaction, we show that, while the single-particle excitation gap becomes large, the velocity of collective Goldstone mode becomes small. As a result, the origin of temperature dependence of a physical quantity continuously changes from single-particle excitations to collective excitations, as one passes through the BCS-BEC crossover region. To see this, we examine the superfluid density.

AB - We investigate superfluid properties of a two-component Fermi gas in the BCS-BEC crossover region. Including strong-coupling effects within a Gaussian fluctuation approximation, we self-consistently determine the superfluid order parameter and chemical potential at finite temperatures. Using these self-consistent solutions, we calculate single-particle excitations, as well as collective mode, over the entire BCS-BEC crossover region. As one increases the strength of a pairing interaction, we show that, while the single-particle excitation gap becomes large, the velocity of collective Goldstone mode becomes small. As a result, the origin of temperature dependence of a physical quantity continuously changes from single-particle excitations to collective excitations, as one passes through the BCS-BEC crossover region. To see this, we examine the superfluid density.

KW - BCS-BEC crossover

KW - Superfluid Fermi gas

KW - Superfluid density

UR - http://www.scopus.com/inward/record.url?scp=84903839409&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84903839409&partnerID=8YFLogxK

U2 - 10.1142/9789814282130_0007

DO - 10.1142/9789814282130_0007

M3 - Conference contribution

AN - SCOPUS:84903839409

SN - 981428212X

SN - 9789814282123

T3 - Proceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008

SP - 18

EP - 23

BT - Proceedings of the 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008

PB - World Scientific Publishing Co. Pte Ltd

T2 - 9th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology, ISQM-Tokyo 2008

Y2 - 25 August 2008 through 28 August 2008

ER -