Longitudinal and transverse thermoelectric transport in MnSi

We have investigated the longitudinal and transverse thermoelectric phenomena (Seebeck and Nernst effects) in a single crystal of intermetallic compound MnSi. The Seebeck coefficient is largely decreased (≈50%) by magnetic field around the helimagnetic transition temperature, which implies the large entropy release at the magnetic transition. We have discerned the anomalous and normal components of Nernst signal dependent on the magnetization and the magnetic field, respectively. For the anomalous Nernst effect, the intrinsic mechanism induced by the Berry phase of electrons seems dominant over the extrinsic mechanisms induced by scattering at least in the high temperature (T≥15 K) and resistive (ρ>4 μΩcm) region. The Nernst and Seebeck signals show little change in the course of the transition to skyrmion crystal.