THE ROLE OF CHAIN SUPERCONDUCTIVITY IN THE 123-HTSC - A MICROSCOPIC APPROACH

A plane-chain model of superconductivity is proposed for the high temp erature superconductor YBa2Cu3O7-x. The pair condensation which is ass umed to occur in both the 2D CuO2 planar sheets and the 1D CuO chains is assumed to be due to the exchanges of the spin fluctuations in shee ts and in chains. The carriers in the sheets are coupled to those in t he chains by two particle (pair) tunneling. The effect of this couplin g on the T-c are examined by looking at the one loop corrections to th e Eliashberg equations. The resulting strong coupling expressions for the T-c are very similar to the one previously obtained in a Ginzburg- Landau analysis of the model. (C) 1998 Elsevier Science Ltd. All right s reserved.