Magnetoresistance and Kohler rule in the topological chiral semimetal CoSi
A. E. Petrova, O. A. Sobolevskiy, С. М. Стишов
Abstract
The transverse and longitudinal magnetoresistance (MR) of two samples of the topological chiral semimetal CoSi with different residual resistivity ratios (RRRs) was studied. It is shown that the Kohler rule works for the transverse MR. The Kohler rule is also fulfilled in the case of longitudinal MR at a low reduced magnetic field. A sharp deviation in the longitudinal MR curve for the sample with low RRR from the Kohler prediction at high fields reveals its tendency to change sign at higher magnetic fields. We probably do not see any specific MR features connected to the topological chiral anomaly in the electron spectra of CoSi. This observation implies the need for certain revisions of the theoretical predictions. Shubnikov--de Haas quantum oscillations were observed and analyzed in both perpendicular and parallel configurations of the current and magnetic field in sample CoSi-1 with $\mathrm{RRR}=9.33$ at low temperatures.