Altermagnetic spin-split Fermi surfaces in CrSb revealed by quantum oscillation measurements
arXiv:2601.19105
The authors combine high‑field magnetotransport, torque measurements, and DFT+U calculations with spin‑orbit coupling to map the spin‑split Fermi surfaces of the altermagnet CrSb, revealing closed pockets at the A point.
Abstract
We report a comprehensive quantum oscillation study of the prototypical altermagnet CrSb, combining high-field magnetotransport and torque measurements with DFT + calculations including spin-orbit coupling. Multiple quantum oscillation frequencies were observed and tracked over wide angular ranges. The measured frequency branches are consistently explained by the spin-split Fermi surfaces arising from the altermagnetic electronic structure. Our determined Fermi surface reveals that bands 1 and 2 form closed pockets centered at the A point, rather than the tubular -axis-open sheets or -centered closed pockets proposed in previous studies. Our findings establish the Fermi-surface topology of CrSb and provide a firm basis for exploring emergent phenomena in altermagnetic materials.
7 pages, 4 figures + SM (11 pages, 5 figures, 1 table)