Nonmonotonic temperature dependence of thermopower in strongly correlated electron systems

強相関電子系における熱起電力の非単調な温度依存性

松尾 まり; 岡本 敏史*; 小椎八重 航*; 森 道康  ; 前川 禎通

Matsuo, Mari; Okamoto, Satoshi*; Koshibae, Wataru*; Mori, Michiyasu; Maekawa, Sadamichi

We examine the temperature dependence of thermopower in the single band Hubbard model using dynamical mean-field theory. The strong Coulomb interaction brings about the coherent-to-incoherent crossover as temperature increases. As a result, the thermopower exhibits non-monotonic temperature dependence and asymptotically approaches values given by the Mott-Heikes formula. In the light of our theoretical result, we discuss the thermopower in some transition metal oxides. The magnetic field dependence of the thermopower is also discussed.