CALCULATION OF THE TRANSVERSE NUCLEAR-RELAXATION RATE FOR YBA2CU3O7 IN THE SUPERCONDUCTING STATE

The importance of the electronic spin fluctuations in the CuO2 planes in the theory of the transverse nuclear relaxation for YBa2Cu3O7 has been demonstrated by Pennington and Slichter. We present the predictions of an RPA-like theory for the transverse nuclear relaxation time, tau, in the superconducting state. s- and d-wave gap symmetries yield distinctively different results for tau-1; for an s-wave gap tau-1 decays rapidly below T(c), while for a d-wave gap it remains nearly constant. Measurements of tau-1 below T(c) could provide valuable information about the symmetry of the superconducting state. Results for the temperature dependence of tau-1 in the normal state are also given.