Extreme magnetoresistance and Shubnikov-de Haas oscillations in ferromagnetic DySb

TL;DR

This study investigates the electronic structure and extreme magnetoresistance in ferromagnetic DySb, revealing high mobility and Shubnikov-de Haas oscillations, while ruling out topological and compensation effects as causes.

Contribution

It provides a comprehensive experimental and theoretical analysis of DySb's electronic properties and clarifies the origin of its large magnetoresistance.

Findings

Observed extremely large positive magnetoresistance up to 3.7×10^4% at 1.8 K and 38.7 T.

Detected Shubnikov-de Haas oscillations consistent with first principles calculations.

Ruled out topological and compensation effects as causes of XMR, attributing it to high mobility from steep linear bands.

Abstract

The electronic structures of a representative rare earth monopnictide (i.e., DySb) under high magnetic field (i.e., in the ferromagnetic state) are studied from both experimental and theoretical aspects. A non-saturated extremely large positive magnetoresistance (XMR) is observed (as large as 3.7*10^4% at 1.8 K and 38.7 T), along with the Shubnikov-de Haas oscillations that are well reproduced by our first principles calculations. Three possible origins of XMR are examined. Although a band inversion is found theoretically, suggesting that DySb might be topologically nontrivial, it is deeply underneath the Fermi level, which rules out a topological nature of the XMR. The total densities of electron-like and hole-like carriers are not fully compensated, showing that compensation is unlikely to account for the XMR. The XMR is eventually understood in terms of high mobility that is associated with the steep linear bands. This discovery is important to the intensive studies on the XMR of rare earth monopnictides.