Quantum oscillations and electronic structures in large Chern number semimetal RhSn

TL;DR

This study investigates the electronic properties and quantum oscillations in RhSn, a large Chern number semimetal, revealing its complex Fermi surface, high mobility, and topological characteristics consistent with theoretical predictions.

Contribution

It provides detailed experimental evidence of quantum oscillations and electronic structures in RhSn, confirming its topological features and large Chern number through combined measurements and calculations.

Findings

Large unsaturated magnetoresistance observed.

Multiple quantum oscillation frequencies identified.

Berry phases consistent with Chern number ±4.

Abstract

We report the magnetoresistance, Hall effect, de Haas-van Alphen (dHvA) oscillations and the electronic structures of single crystal RhSn, which is a typical material of CoSi family holding a large Chern number. The large unsaturated magnetoresistance is observed with B//[001]. The Hall resistivity curve indicates that RhSn is a multi-band system with high mobility. Evident quantum oscillations have been observed, from which the light effective masses are extracted. Ten fundamental frequencies are extracted after the fast Fourier transform analysis of the dHvA oscillations with B//[001] configuration. The two low frequencies F$_1$ and F$_2$ do not change obviously and the two high frequencies F$_9$ and F$_{10}$ evolve into four when B rotates from B//[001] to B//[110], which is consistent with the band structure in the first-principles calculations with spin-orbit coupling (SOC). The extracted Berry phases of the relative pockets show a good agreement with the Chern number $\pm4$ (with SOC) in the first-principles calculations. Above all, our studies indicate that RhSn is an ideal platform to study the unconventional chiral fermions and the surface states.