Superconducting Pseudogap in a Boson-Fermion Model

作者：Mamedov Tofik^*; de Llano Manuel

来源：Journal of the Physical Society of Japan, 2010, 79(4): 044706.

DOI：10.1143/JPSJ.79.044706

• cuprate superconductivity
• resonant Cooper pairs
• boson-fermion models
• Bose-Einstein condensation
• pseudogap

A boson-fermion (BF) quantum-statistical binary gas mixture model consisting of positive-energy resonant bosonic Cooper electron pairs (CPs) in chemical and thermal equilibrium with single unpaired electrons is presented. Two-time retarded Green functions are shown to conveniently cope and deal with nonzero center-of-mass momentum (CMM) CPs. They yield an analytic expression for a dimensionless-coupling coupling (lambda)- and temperature (T)-dependent generalized energy gap E(g)(lambda, T) in the single-electron spectrum of a superconductor. This generalized gap vanishes above a specific ("depairing'' or "pseudogap'') temperature T* > T(c), where T(c) is the critical Bose-Einstein condensation (BEC) singularity associated with the BF binary mixture, but is nonzero for all T below T* due initially to the formation of "preformed'' pairs. Within the present BF model the generalized gap E(g) (lambda,T) is not restricted to the underdoped high-temperature supercondu

• 出版日期2010-4