Electronic and magnetic structures studies of Altermagnets

Traditional ordered magnetic phases are traditionally divided into ferromagnetism (FM) and antiferromagnetism (AFM) based on the arrangement of spin polarization. Recently, a new magnetic phase named altermagnetism was theoretically proposed, expanding our understanding of magnetism. In this novel magnetic phase, all the bands split into spin-up/down states analogous to those in FM materials, but the net magnetization remains zero, similar to AFM materials. This unique property makes it a promising platform for researching novel physical phenomena, such as giant magnetoresistance, anomalous Hall effect, and C-paired spin-valley locking. Recent theoretical works have identified several promising materials exhibiting this new form of magnetism. Among them, RuO2, MnTe, and CrSb are considered the most suitable candidates due to their large spin band splitting and high Neel temperature exceeding room temperature. Several ARPES studies have been dedicated to uncovering the band splitting induced by altermagnetism in MnTe; however, many details remain unclear. With this proposal, our goal is to thoroughly elucidate the altermagnetic band structure of CrSb, which displays a substantial spin band splitting of over 1.0 eV and a Neel temperature exceeding 700 K. By utilizing VUV and soft X-ray ARPES at LOREA ALBA, we expect to discover key evidence of band splitting in the first altermagnetic metal, CrSb.