ELECTRONIC PAIRING AND VARIATION IN THE NORMAL STATE OF METAL

Abstract

Reviewing the situation of the experimental studies of the normal state in high-Tc super-conductors (HTS), we have put forward nine points to be necessarily considered in any theory of the normal state in HTS. It is argued that the two-dimension two-subsystem model is at least qualitatively consistent with all these nine points. On the basis of these arguments, the problem of the electronic pairing and variation in the normal state of metal has been discussed. We have put forward three variation of metals, i.e. the conventional metal (Fermi liquid), near conventional metal and the metal with the markedly pseudogapped metallic behaviour which may be a marginal Fermi liquid.