ANTIFERROMAGNETIC SPIN FLUCTUATIONS AND SUPERCONDUCTIVITY IN HIGH-TC OXIDES

It is shown that anomalous physical properties of high T(c) oxides as observed in the electrical resistivity, infrared conductivity, NMR relaxation rate, etc. above their transition temperatures are well explained in terms of antiferromagnetic spin fluctuations in two dimensional metals described by the self-consistent renormalization (SCR) theory of spin fluctuations. Some of the comparisons between theory and experiment go to a quantitative level including no adjustable parameter. Superconductivity due to the spin fluctuation mechanism is treated by using the weak coupling and the strong coupling theories. The order parameter is shown to be of B1g character and the critical temperature is evaluated to be of the right order of magnitude.