Effect of uniaxial stress on T-c and the vanHove scenario in YBa2Cu3O7

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.