Quantitate evaluation of the thermoelectric power of (Bi,Pb)₂ Sr₂CaCu₂O_8+δ from the experimentally determined electronic structure

Energy-momentum (ε{lunate} - over(k, →)) dispersion of the overdoped (Bi,Pb)₂Sr₂CaCu₂O_8+δ with the superconducting transition temperature of 66 K was determined by the high-resolution angle resolved photoemission spectroscopy (ARPES). Bilayer-splitting caused by the two CuO₂ planes in the basis was clearly observed in the present ARPES measurements. Spectral conductivity σ (ε{lunate}) was calculated from the determined ε{lunate} (over(k, →)) by taking the bilayer splitting into account with employing the Boltzmann transport equation. The calculated thermoelectric power S (T) form thus determined σ (ε{lunate}) reproduced extremely well the observed one, strongly indicating the important role of the electronic structure on the temperature dependence of S (T) in the cuprate superconductors. The bilayer-splitting certainly provides a finite contribution to the temperature dependence of S (T) but it is too trivial to significantly affect the strong hole-concentration dependence of S (T).