• thermoelectric power;
  • high-Tc cuprates;
  • pseudogap.


Thermoelectric power (TEP) of high-Tc superconductors has been investigated in a wide range of temperature (Tc < T < 700 K) for La2-xSrxCuO4. For wide doping level from underdoping to heavily overdoping, TEP follows the linear-T dependence above the broad peak temperature, Tp. At high temperatures, however, TEP shows deviation from the linear-T dependence at a certain temperature Th, which is pronounced with doping up to x ∼ 0.2 and turns to be suppressed for further doping. The systematic change of the characteristic temperatures, Tc, Tp, and Th discussed in terms of the crossover behavior from a pseudogap state to strange metal in the underdoped regime and from strange metal to conventional metal in the overdoped regime.