We study the two-dimensional spin-charge separated Ginzburg-Landau theory containing U(1) gauge interactions as a semi-phenomenological model describing fluctuating condensates in high temperature superconductivity. Transforming the original GL action, we abstract the effective action of Cooper pair. Especially, we clarify how Cooper pair correlation evolves in the normal state from the point of view of spin-charge separation. Furthermore, we point out how Cooper pair couples to gauge field in a gauge-invariant way, stressing the insensitivity of Cooper pair to infrared gauge field fluctuation.We study the two-dimensional spin-charge separated Ginzburg-Landau theory containing U(1) gauge interactions as a semi-phenomenological model describing fluctuating condensates in high temperature superconductivity. Transforming the original GL action, we abstract the effective action of Cooper pair. Especially, we clarify how Cooper pair correlation evolves in the normal state from the point of view of spin-charge separation. Furthermore, we point out how Cooper pair couples to gauge field in a gauge-invariant way, stressing the insensitivity of Cooper pair to infrared gauge field fluctuation.

arXiv:cond-mat/0006097Journal of the Physical Society of JapanFeb 15, 20010 citations

Interacting preformed Cooper pairs in resonant Fermi gases

K. B. Gubbels, Henk T. C. Stoof

We consider the normal phase of a strongly interacting Fermi gas, which can have either an equal or an unequal number of atoms in its two accessible spin states. Due to the unitarity-limited attractive interaction between particles with different spin, noncondensed Cooper pairs are formed. The starting point in treating preformed pairs is the Nozi\`eres-Schmitt-Rink (NSR) theory, which approximates the pairs as being noninteracting. Here, we consider the effects of the interactions between the Cooper pairs in a Wilsonian renormalization-group scheme. Starting from the exact bosonic action for the pairs, we calculate the Cooper-pair self-energy by combining the NSR formalism with the Wilsonian approach. We compare our findings with the recent experiments by Harikoshi et al. [Science 327, 442 (2010)] and Nascimb\`ene et al. [Nature (London) 463, 1057 (2010)], and find very good agreement. We also make predictions for the population-imbalanced case, which can be tested in experiments.We consider the normal phase of a strongly interacting Fermi gas, which can have either an equal or an unequal number of atoms in its two accessible spin states. Due to the unitarity-limited attractive interaction between particles with different spin, noncondensed Cooper pairs are formed. The starting point in treating preformed pairs is the Nozi\`eres-Schmitt-Rink (NSR) theory, which approximates the pairs as being noninteracting. Here, we consider the effects of the interactions between the Cooper pairs in a Wilsonian renormalization-group scheme. Starting from the exact bosonic action for the pairs, we calculate the Cooper-pair self-energy by combining the NSR formalism with the Wilsonian approach. We compare our findings with the recent experiments by Harikoshi et al. [Science 327, 442 (2010)] and Nascimb\`ene et al. [Nature (London) 463, 1057 (2010)], and find very good agreement. We also make predictions for the population-imbalanced case, which can be tested in experiments.

arXiv:1102.4751Physical Review AJul 21, 201114 citations

Stable and resonant Cooper pairs

Valdir C. Aguilera-Navarro, Mauricio Fortes, MANUEL DE LLANO

Solid State CommunicationsDec 11, 200318 citations

Cooper pairing in ultracold 40K using Feshbach resonances

John L. Bohn

We point out that the fermionic isotope ${}^{40}\mathrm{K}$ is a likely candidate for the formation of Cooper pairs in an ultracold atomic gas. Specifically, in an optical trap that simultaneously traps the spin states $|9/2,\ensuremath{-}9/2〉$ and $|9/2,\ensuremath{-}7/2〉,$ there exists a broad magnetic-field Feshbach resonance at ${B=196}_{\ensuremath{-}21}^{+9}$ G that can provide the required strong attractive interaction between atoms. An additional resonance, at ${B=191}_{10}^{+5}$ G, could generate p-wave pairing between identical $|9/2,\ensuremath{-}7/2〉$ atoms. A Cooper-paired degenerate Fermi gas could thus be constructed with existing ultracold-atom technology.We point out that the fermionic isotope ${}^{40}\mathrm{K}$ is a likely candidate for the formation of Cooper pairs in an ultracold atomic gas. Specifically, in an optical trap that simultaneously traps the spin states $|9/2,\ensuremath{-}9/2〉$ and $|9/2,\ensuremath{-}7/2〉,$ there exists a broad magnetic-field Feshbach resonance at ${B=196}_{\ensuremath{-}21}^{+9}$ G that can provide the required strong attractive interaction between atoms. An additional resonance, at ${B=191}_{10}^{+5}$ G, could generate p-wave pairing between identical $|9/2,\ensuremath{-}7/2〉$ atoms. A Cooper-paired degenerate Fermi gas could thus be constructed with existing ultracold-atom technology.

arXiv:cond-mat/9911132Physical Review AApr 17, 200078 citations

The Cooper pair dispersion relation

M. Casas, Shigeji Fujita, MANUEL DE LLANO +3 more

Physica C SuperconductivityJan 1, 199824 citations

We point out that the fermionic isotope

{}^{40}\mathrm{K}

is a likely candidate for the formation of Cooper pairs in an ultracold atomic gas. Specifically, in an optical trap that simultaneously traps the spin states $|9/2,\ensuremath{-}9/2〉$ and $|9/2,\ensuremath{-}7/2〉,$ there exists a broad magnetic-field Feshbach resonance at ${B=196}_{\ensuremath{-}21}^{+9}$ G that can provide the required strong attractive interaction between atoms. An additional resonance, at

{B=191}_{10}^{+5}

G, could generate p-wave pairing between identical $|9/2,\ensuremath{-}7/2〉$ atoms. A Cooper-paired degenerate Fermi gas could thus be constructed with existing ultracold-atom technology.