High magnetic field study of ${\mathrm{CePd}}_2{\mathrm{Si}}_2$

The de Haas–van Alphen (dHvA) effect in the heavy fermion system ${\mathrm{CePd}}_2{\mathrm{Si}}_2$ was studied by magnetic torque measurements in magnetic fields up to 28 T at low temperature. A clear magnetic torque anomaly observed at $B_m\sim 10\mathrm{T}$ applied along the crystallographic a axis indicates a metamagnetic transition. The transition also manifests itself by a sharp drop of the magnetoresistance at low temperature. The dHvA oscillations observed above the transition reveal six different frequencies in the basal plane with the corresponding effective masses from ${6m}_e$ to ${23m}_e.$ Comparison of the angular dependence of the dHvA frequencies with the theoretical band-structure calculations implies that the $4f$ electrons are itinerant rather than localized inside a magnetically ordered state. One frequency is split into two close satellites, which most likely originate from the up and down spin bands, whose effective masses differ by a factor of 2. The spin splitting gives rise to an apparent anomalous field dependence of the effective mass obtained from the experiment.