Altermagnetic spin-split Fermi surfaces in CrSb revealed by quantum oscillation measurements

TL;DR

This study provides bulk-sensitive experimental evidence of altermagnetic spin-split Fermi surfaces in CrSb through quantum oscillation measurements, combining experimental data with theoretical calculations.

Contribution

It is the first comprehensive quantum oscillation analysis confirming the bulk altermagnetic spin-split Fermi surfaces in CrSb, supported by DFT+$U$ calculations.

Findings

Identification of multiple quantum-oscillation frequencies from four spin-non-degenerate bands

Definitive evidence of bulk altermagnetic spin-split Fermi surface in CrSb

Correlation between experimental measurements and theoretical calculations

Abstract

Altermagnets, a class of collinear magnets defined by their spin-split electronic bands, are a focus of intense research, where a key challenge is to experimentally verify this unique band structure as a bulk property. Here, we report a comprehensive quantum oscillation study on the prototypical altermagnet CrSb. By combining high-field magnetotransport and torque measurements with DFT+$U$ calculations including spin-orbit coupling, we successfully identify a multitude of quantum-oscillation frequencies originating from four spin-non-degenerate bands. These results provide definitive, bulk-sensitive evidence for the altermagnetic spin-split Fermi surface of CrSb, which provides a firm foundation for exploring its novel electronic properties.