Giant generic topological Hall resistivity of MnSi under pressure

Abstract

We report detailed low temperature magnetotransport and magnetization measurements in MnSi under pressures up to $\sim 12\mathrm{kbar}$. Tracking the role of sample quality, pressure transmitter, and field and temperature history allows us to link the emergence of a giant topological Hall resistivity $\sim 50\mathrm{n}\hat{\mathrm{I}}\text{c◯}\mathrm{cm}$ to the skyrmion lattice phase at ambient pressure. We show that the remarkably large size of the topological Hall resistivity in the zero-temperature limit must be generic. We discuss various mechanisms which can lead to the much smaller signal at elevated temperatures observed at ambient pressure.