Experimental search for spin splitting in the electronic states of a newly discovered Altermagnet Fe1/4NbS2

Altermagnetism was recently identified as a new type of magnetic phase beyond the conventional dichotomy of ferromagnetism (FM) and antiferromagnetism (AFM). Its globally compensated magnetization and directional spin polarization promise new properties such as spin-polarized conductivity, anomalous Hall effect, tunneling, and giant magnetoresistance that are highly useful for next-generation memory devices, magnetic detectors, and energy conversion. The layered intercalated transition metal dichalcogenide (ITMD) Fe1/4NbS2 has been recently identified as an altermagnet, exhibiting A-type antiferromagnetic order (TN =150 K) with spin-split bands. Our study aims to utilize high-resolution and spin-resolved angle-resolved photoemission spectroscopy (Spin-ARPES) to directly probe the spin-split electronic band structure and Fermi surface topology of Fe1/4NbS2. These measurements will provide crucial experimental validation of the predicted altermagnetic state and offer insights into its electronic and spin properties, paving the way for novel spintronic applications.