Gap anisotropy in high-Tc superconductors: A unified picture

I propose a synthesis of the results of several different gap-measurement technqiues by means of a phenomenological, anisotropic model for the energy gap. This model, which has a large gap in the a-b plane crystalline direction, and a smaller BCS-sized gap in the c-axis direction, is chosen to be consistent with recent infrared, Raman, photoemission, and high-resolution electron-energy-loss data. I show in this paper that it is also consistent with point-contact tunneling data. © 1990 The American Physical Society.