Theory of Thermoelectric Power in High-T_c Superconductors

Abstract

We present a microscopic theory for the thermoelectric power (TEP) in high-T_c cuprates. Based on the general expression for the TEP, we perform the calculation of the TEP for a two-dimensional Hubbard model including all the vertex corrections necessary to satisfy the conservation laws. In the present study, characteristic anomalous temperature and doping dependences of the TEP in high-T_c cuprates, which have been a long-standing problem in high-T_c cuprates, are well reproduced for both hole- and electron-doped systems, except for the heavily under-doped case. According to the present analysis, the strong momentum and energy dependences of the self-energy due to the strong antiferromagnetic fluctuations play an essential role in reproducing experimental anomalies of the TEP.