Efeitos da paridade da hibridização em supercondutores multibandas

Abstract

Recent studies have shown that antisymmetric hybridization favors the formation of bound states among the quasiparticles, and this is the main mechanism of the enhancement of the superconductivity in two-band systems. In this work, we study a generic two-band superconducting system, which forms intraband Cooper pairs and a term that’s responsible for the creation of Cooper’ pairs formed by fermions from different bands. The hybridization plays the role to transfer the quasiparticles among the bands and it can be tuned experimentally by an external factor like pressure or doping, allowing to explore the phase diagrams. Thus, the model is quite general, and we have the proposal to discuss the differences that hybridization parity acts in the purely intraband and interband case. The excitation energies as well the gap equation are obtained using the Green function’s method, and it had found the purely intraband case is no dependent of the hybridization parity. In the case of symmetric hybridization, the intraband case shows a discontinuity in the order parameter, a fact that doesn’t occur in the antisymmetric hybridization.