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

TL;DR

This study reveals that ScSb exhibits extremely large magnetoresistance and provides a complete mapping of its Fermi surface, showing it is a nearly compensated semimetal with unique electronic features.

Contribution

The paper presents the first full determination of the Fermi surface in ScSb, including the elusive $eta_3$ pocket, and links its large magnetoresistance to electron-hole compensation.

Findings

Magnetoresistance reaches ~28000% at 2 K and 14 T.

Complete Fermi surface topology including $eta_3$ pocket.

ScSb is a nearly compensated semimetal with n/p ≈ 0.93.

Abstract

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.