Origin of extremely large magnetoresistance in the semimetal YSb*

The discovery of nonsaturating and extremely large magnetoresistance (XMR) in the semimetal WTe2 in 2014 triggered extensive research to uncover the origin of XMR, which has also been observed in many nonmagnetic materials. Recently, XMR was observed in the rare-earth monopnictides LnX (Ln = La, Y, Nd, Ce and X = Sb, Bi). Here we report on magnetoresistivity measurements to uncover the origin of the nonsaturating XMR in YSb. We measured angle-dependent Shubnikov–de Haas (SdH) oscillations to determine the shape and volume of the Fermi surface. Our results show that YSb has nearly compensated densities of electrons and holes. We can describe both transverse and hall magnetoresistivities with a semiclassic theory by including contributions from all the isotropic and anisotropic Fermi pockets. We demonstrate that the XMR in YSb originates from the high mobility and nearly prefect compensation of electrons and holes.