Skyrmion contribution to thermopower of MnSi

Skyrmions have recently been theoretically predicted [1] and experimentally observed [2] in MnSi. To identify whether skyrmions contribute to thermoelectric transport, we present a detailed map of the temperature, pressure and magnetic field behavior of thermopower $S$ in MnSi. $S/T(p,T)$ confirms the established phase diagram with Fermi liquid, non-Fermi liquid and partial order phases. In the high pressure non-Fermi liquid phase, $S(T)$ increases in the vicinity of the boundary with the Fermi liquid phase, at critical pressure $p_c\sim14.5$ kbar. This may be linked to the scattering of conduction electrons on fluctuating amorphous skyrmions [1]. On the contrary, the thermopower decreases when an ordered lattice of skyrmions is established in the magnetic field. A small suppression of $S(T)$ is observed in a narrow region, for 27 K $