Extremely large magnetoresistance and the complete determination of the Fermi surface topology in the semimetal ScSb

We report the magnetoresistance of ScSb, which is a semimetal with a simple rocksalt-type structure. We found that the magnetoresistance reaches $\sim$28000 % at 2 K and 14 T in our best sample, and it exhibits a resistivity plateau at low temperatures. The Shubnikov-de Haas oscillations extracted from the magnetoresistance data allow the full construction of the Fermi surface, including the so-called $\alpha_3$ pocket which has been missing in other closely related monoantimonides, and an additional hole pocket centered at $\Gamma$. The electron concentration ($n$) and the hole concentration ($p$) are extracted from our analysis, which indicate that ScSb is a nearly compensated semimetal with $n/p\approx0.93$. The calculated band structure indicates the absence of a band inversion, and the large magnetoresistance in ScSb can be attributed to the nearly perfect compensation of electrons and holes, despite the existence of the additional hole pocket.