Contribution of electronic structure to thermoelectric power in (Bi,Pb)2 (Sr,La)2 Cu O6+δ

The energy-momentum (ε-k) dispersion and the shape of the Fermi surface in the (Bi,Pb)2 (Sr,La)2 Cu O6+δ (Bi2201) superconductors with various hole concentrations were determined by the high resolution angle-resolved photoemission spectroscopy. On the basis of the ε-k dispersion thus obtained, temperature and hole-concentration dependence of the thermoelectric power S (T) was calculated within the framework of the Boltzmann transport theory. S (T) of the optimally and overdoped samples was quantitatively reproduced by the present calculation, strongly indicating that characteristics in S (T) of the high- Tc cuprates under the optimally to overdoped conditions is unambiguously caused by the band structure characterized by the van Hove singularity near the Fermi level.