Theory of the electronic structure and spin susceptibility of La2-xSrxCuO4

We solve the problem of the effect of strong electron correlations on the homogeneous spin susceptibility of current carriers in CuO2 planes. We show that the dependence of the spin susceptibility X(T) of high-T-c superconductors of the La2-xSrxCuO4 type on temperature and the doping index x can be explained fairly well by the two-band model suggested earlier (the singlet-correlated oxygen band plus the lower Hubbard band of copper). The model has features in common with the phenomenological t-J model but cannot be reduced to the latter completely. In contrast to the t-J model, the density of states of the oxygen holes has a peak near the bottom of the band. It is the presence of this peak together with the non-Fermi-liquid properties that explain the unusual behavior of the spin susceptibility of La2-xSrxCuO4. (C) 1997 American Institute of Physics.