Effects of Spin and Orbital Degeneracy on the Thermopower of Strongly Correlated Systems

We study thermopower in strongly correlated electron systems with orbital degeneracy using numerical diagonalization method on finite-size clusters. It is shown that the thermopower is strongly enhanced by the spin and orbital degrees of freedom, but the resistivity is significantly less affected. A key for the strategy of new thermoelectric materials in transition metal oxides is proposed in the light of the theory.