Van Hove scenario and the eight-band model for high-Tc superconductors.

Szotek Z., Gyorffy B. L., Temmerman W. M., Andersen O. K.

Serc Daresbury Lab Warrington Wa4 4ad Cheshire England
Univ Bristol Hh Wills Phys Lab Bristol Bs8 1tl Avon England
Max Planck Inst Festkorperforsch D-70506 Stuttgart Germany

We investigate the doping dependence of the superconducting transition temperature T-c for the cuprate superconductors on the basis of a semiphenomenological description of pairing and the eight-band model for their electronic structure in the normal state. We find, in agreement with experiments, that T-c rises and then falls steeply as the number of holes increases from underdoping to overdoping. We identify the characteristic saddle points of the eight-band model as the cause of this behavior. Because our description of pairing is semiphenomenological, we shed new light on the physical mechanism of pairing only indirectly, nevertheless we present new evidence that the above Van Hove-like scenario is an essential feature of superconductivity in these, materials. [S0163-1829(98)03025-2].

A reprint of this paper can be obtained here.

Physical Review B, 58 522-526, 1998.

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