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
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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 -