Superconducting Pseudogap in a Boson–Fermion Model

スポンサーリンク

概要

• 論文の詳細を見る

• 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 ($\lambda$)- and temperature ($T$)-dependent generalized energy gap $E_{\text{g}}(\lambda,T)$ in the single-electron spectrum of a superconductor. This generalized gap vanishes above a specific (“depairing” or “pseudogap”) temperature $T^{\ast}>T_{\text{c}}$, where $T_{\text{c}}$ is the critical Bose–Einstein condensation (BEC) singularity associated with the BF binary mixture, but is nonzero for all $T$ below $T^{\ast}$ due initially to the formation of “preformed” pairs. Within the present BF model the generalized gap $E_{\text{g}}(\lambda,T)$ is not restricted to the underdoped high-temperature superconductors as we illustrate with BSCCO, but is also applicable in optimally-doped and even overdoped compounds for which $T^{\ast}$ and $T_{\text{c}}$ virtually coincide as in BCS theory where nonzero-CMM CPs are neglected.

• 2010-04-15

著者

• Mamedov Tofik

  Faculty of Engineering, Baskent University, 06530 Ankara, Turkey

• de Llano

  Physics Department, University of Connecticut, Storrs, CT 06269, U.S.A.

関連論文

• Generalized Superconducting Gap in an Anisotropic Boson--Fermion Mixture with a Uniform Coulomb Field
• Superconducting Pseudogap in a Boson–Fermion Model

スポンサーリンク