Pairing in quantum critical systems: Transition temperature, pairing gap, and their ratio

Pairing transition of nuclei at finite temperature

Pairing transition at finite temperature was investigated by the shell model and BCS calculations. The definitive signature of pairing transition is identified by a “transition temperature” Tt estimated from a “thermal” odd-even mass difference, while there is no sharp phase transition because of the finiteness of nucleus. It is found that Tt is in good agreement with predictions of critical te...

Finite-temperature pairing gap of a unitary fermi gas by quantum monte carlo calculations.

We calculate the one-body temperature Green's (Matsubara) function of the unitary Fermi gas via quantum Monte Carlo, and extract the spectral weight function A(p,omega) using the methods of maximum entropy and singular value decomposition. From A(p,omega) we determine the quasiparticle spectrum, which can be accurately parametrized by three functions of temperature: an effective mass m{*}, a me...

Pairing gap and in-gap excitations in trapped fermionic superfluids.

We consider trapped atomic Fermi gases with Feshbach-resonance enhanced interactions in pseudogap and superfluid temperatures. We calculate the spectrum of radio-frequency (or laser) excitations for transitions that transfer atoms out of the superfluid state. The spectrum displays the pairing gap and also the contribution of unpaired atoms, that is, in-gap excitations. The results support the c...

Pairing correlations near a Kondo-destruction quantum critical point

J. H. Pixley,1,2 Lili Deng,3 Kevin Ingersent,3 and Qimiao Si2 1Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA 2Department of Physics and Astronomy, Rice University, Houston, Texas 77005-1827, USA 3Department of Physics, University of Florida, Gainesville, Florida 32611-8440, USA (Received 17 Augus...

Quantum pairing of impurities in quantum crystals.