We discuss the superfluid phase transition in a gas of Fermi atoms with a Feshbach resonance. A tunable pairing interaction associated with the Feshbach resonance is shown to naturally lead to the BCS-BEC crossover, where the character of superfluidity continuously changes from the weak-coupling Bardeen-Cooper-Schrieffer (BCS) type to the Bose-Einstein condensation (BEC) of tightly bound molecules, as one decreases the threshold energy 2ν of the Feshbach resonance. We also discuss effects of a trap, as well as the p-wave BCS-BEC crossover adjusted by a p-wave Feshbach resonance.We discuss the superfluid phase transition in a gas of Fermi atoms with a Feshbach resonance. A tunable pairing interaction associated with the Feshbach resonance is shown to naturally lead to the BCS-BEC crossover, where the character of superfluidity continuously changes from the weak-coupling Bardeen-Cooper-Schrieffer (BCS) type to the Bose-Einstein condensation (BEC) of tightly bound molecules, as one decreases the threshold energy 2ν of the Feshbach resonance. We also discuss effects of a trap, as well as the p-wave BCS-BEC crossover adjusted by a p-wave Feshbach resonance.

International Journal of Modern Physics BDec 15, 20061 citation

フェルミ原子ガスの新しい超流動 : BCS-BECクロスオーバーの実現(最近のトピックス)

洋士大橋

日本物理學會誌Apr 5, 20040 citations

Bogoliubov theory of Feshbach molecules in the BEC-BCS crossover

M. W. J. Romans, Henk T. C. Stoof

We present the Bogoliubov theory for the Bose-Einstein condensation of Feshbach molecules in a balanced Fermi mixture. Because the Bogoliubov theory includes (Gaussian) fluctuations, we can in this manner accurately incorporate both the two-body and many-body aspects of the BEC-BCS crossover that occurs near a Feshbach resonance. We apply the theory in particular to the very broad Feshbach resonance in atomic $^{6}\mathrm{Li}$ at a magnetic field of ${B}_{0}=834\phantom{\rule{0.3em}{0ex}}\mathrm{G}$ and find good agreement with experiments in that case. The BEC-BCS crossover for more narrow Feshbach resonances is also discussed.We present the Bogoliubov theory for the Bose-Einstein condensation of Feshbach molecules in a balanced Fermi mixture. Because the Bogoliubov theory includes (Gaussian) fluctuations, we can in this manner accurately incorporate both the two-body and many-body aspects of the BEC-BCS crossover that occurs near a Feshbach resonance. We apply the theory in particular to the very broad Feshbach resonance in atomic $^{6}\mathrm{Li}$ at a magnetic field of ${B}_{0}=834\phantom{\rule{0.3em}{0ex}}\mathrm{G}$ and find good agreement with experiments in that case. The BEC-BCS crossover for more narrow Feshbach resonances is also discussed.

arXiv:cond-mat/0607045Physical Review ANov 17, 200614 citations

冷却原子で探る量子物理の最前線 BCS-BECクロスオーバー

大橋洋士

数理科学Jan 1, 20200 citations

フェルミ粒子系超流動の物理 : BCS-BECクロスオーバーと新しい物質科学(講義ノート)

Yoji Ohashi

Nov 20, 20050 citations

BEC-BCS crossover in an optical lattice

Arnaud Koetsier, D. B. M. Dickerscheid, Henk T. C. Stoof

We present the microscopic theory for the BEC-BCS crossover of an atomic Fermi gas in an optical lattice, showing that the Feshbach resonance underlying the crossover in principle induces strong multiband effects. Nevertheless, the BEC-BCS crossover itself can be described by a single-band model since it occurs at magnetic fields that are relatively far away from the Feshbach resonance. A criterion is proposed for the latter, which is obeyed by most known Feshbach resonances in ultracold atomic gases.We present the microscopic theory for the BEC-BCS crossover of an atomic Fermi gas in an optical lattice, showing that the Feshbach resonance underlying the crossover in principle induces strong multiband effects. Nevertheless, the BEC-BCS crossover itself can be described by a single-band model since it occurs at magnetic fields that are relatively far away from the Feshbach resonance. A criterion is proposed for the latter, which is obeyed by most known Feshbach resonances in ultracold atomic gases.

arXiv:cond-mat/0604186Physical Review ASep 28, 200630 citations

^{6}\mathrm{Li}

at a magnetic field of

{B}_{0}=834\phantom{\rule{0.3em}{0ex}}\mathrm{G}

and find good agreement with experiments in that case. The BEC-BCS crossover for more narrow Feshbach resonances is also discussed.