Effect of gap anisotropy and plasmons on the critical temperature of high-Tc superconductors

Abstract

We study the nature of the transition temperature of a high temperature superconductor with an anisotropic gap using the three square well model of electron-phonon, electron-electron, and electron-plasmon interactions. The critical temperature is calculated as a function of anisotropic parameter and interaction strengths. To show a variety of electron-plasmon coupling constant dependence, λpl, we present curves of transition temperature versus λpl with different values of anisotropic average. We see from these results that both plasmon and anisotropy play key roles in raising the critical temperature of the cuprates and when λpl increases the transition temperature is insensitive to anisotropy. © 1992.