Effect of uniaxial stress on T _c and the van Hove scenario in YBa₂Cu₃O₇

Abstract

The effect of uniaxial stress on T _c in YBa₂Cu₃O₇ is studied within the van Hove scenario including the interlayer coupling (3D effects). The uniaxial pressure along the a or b axis changes the in-plane anisotropy, and that along the c axis increases the interlayer coupling. Both of them change the averaged density of states and so T _c in the framework of the BCS theory. The latter effect on T _c is found to be small compared with the former, which can account for the uniaxial pressure experiment of YBa₂Cu₃O₇.