We present magnetotransport, Seebeck effect, and magnetic torque measurements conducted on the Dirac semimetal PtBi2 single crystals with a temperature range of 1.8–300 K and magnetic field strength up to 14 T. A substantial, nonsaturating magnetoresistance (MR) that reaches 5.15 × 105% at 1.8 K and 9 T obeys a single-parameter scaling, suggesting an effective unified scattering rate across a broad temperature range from 1.8 to 250 K. Importantly, distinct quantum oscillations in the Seebeck coefficient identify multiple extremal orbits with frequencies F = 62.5–1476 T, which are mutually verified by the torque de Haas–van Alphen (dHvA) oscillations and result in small cyclotron masses m* ≈ 0.072–0.16me via Lifshitz–Kosevich analysis. The angular evolution of the dominant frequencies supports three-dimensional multiband pockets/four groups of pockets, and an additional weak branch at F0 ≈ 62.5 T is robust against data-processing variations. Our results establish comprehensive quantum oscillations as a sensitive probe of multiband fermiology and scattering scaling in Dirac semimetals, with implications for understanding the mechanism of extreme MR behavior.
Zhao et al. (Mon,) studied this question.