Finite temperature phase diagrams of a two-band model of superconductivity

摘要

We explore the temperature effects in the superconducting phases of a hybridized two-band system. We show that for zero hybridization between the bands, there are two different critical temperatures. However, for any finite hybridization there is only one critical temperature at which the two gaps vanish simultaneously. We construct the phase diagrams of the critical temperature versus hybridization parameter a and critical temperature versus critical chemical potential asymmetry delta mu between the bands, identifying the superconductor and normal phases in the system. We find an interesting reentrant behavior in the superconducting phase as the parameters alpha or delta mu, which drive the phase transitions, increase. We also find that for optimal values of both alpha and delta mu there is a significant enhancement of the critical temperature of the model. (C) 2018 Elsevier Inc. All rights reserved.