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

Abstract

We report the magnetoresistance of ScSb, which is a semimetal with a simple rocksalt-type structure. We found that the magnetoresistance reaches $\ensuremath{\sim}28\phantom{\rule{0.16em}{0ex}}000%$ 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 ${\ensuremath{\alpha}}_{3}$ pocket which has been missing in other closely related monoantimonides, and an additional hole pocket centered at $\mathrm{\ensuremath{\Gamma}}$. The electron concentration $(n)$ and the hole concentration $(p)$ are extracted from our analysis, which indicates that ScSb is a nearly compensated semimetal with $n/p\ensuremath{\approx}0.93$. 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.