Temperature Dependence of Relativistic Valence Band Splitting Induced by an Altermagnetic Phase Transition

Abstract

Altermagnetic (AM) materials exhibit non-relativistic, momentum-dependent spin-split states, ushering in new opportunities for spin electronic devices. While the characteristics of spin-splitting are documented within the framework of the non-relativistic spin group symmetry, there is limited exploration of the inclusion of relativistic symmetry and its impact on the emergence of a novel spin-splitting in the band structure. This study delves into the intricate relativistic electronic structure of an AM material, alpha-MnTe. Employing temperature-dependent angle-resolved photoelectron spectroscopy across the AM phase transition, the emergence of a relativistic valence band splitting concurrent with the establishment of magnetic order is elucidated. This discovery is validated through disordered local moment calculations, modeling the influence of magnetic order on the electronic structure and confirming the magnetic origin of the observed splitting. The temperature-dependent splitting is ascribed to the advent of relativistic spin-splitting resulting from the strengthening of AM order in alpha-MnTe as the temperature decreases. This sheds light on a previously unexplored facet of this intriguing material. Altermagnets exhibit momentum-dependent spin-split states providing new opportunities for spin electronic devices. Through temperature-dependent angle-resolved photoemission spectroscopy and disordered local moment calculations, it is demonstrated that the relativistic valence band splitting of the prototypical MnTe altermagnet is of magnetic origin. This is attributed to a novel relativistic spin-splitting phenomenon concurrent with the establishment of the altermagnetic order below the N & eacute;el temperature. imageAltermagnetic (AM) materials exhibit non-relativistic, momentum-dependent spin-split states, ushering in new opportunities for spin electronic devices. While the characteristics of spin-splitting are documented within the framework of the non-relativistic spin group symmetry, there is limited exploration of the inclusion of relativistic symmetry and its impact on the emergence of a novel spin-splitting in the band structure. This study delves into the intricate relativistic electronic structure of an AM material, alpha-MnTe. Employing temperature-dependent angle-resolved photoelectron spectroscopy across the AM phase transition, the emergence of a relativistic valence band splitting concurrent with the establishment of magnetic order is elucidated. This discovery is validated through disordered local moment calculations, modeling the influence of magnetic order on the electronic structure and confirming the magnetic origin of the observed splitting. The temperature-dependent splitting is ascribed to the advent of relativistic spin-splitting resulting from the strengthening of AM order in alpha-MnTe as the temperature decreases. This sheds light on a previously unexplored facet of this intriguing material. Altermagnets exhibit momentum-dependent spin-split states providing new opportunities for spin electronic devices. Through temperature-dependent angle-resolved photoemission spectroscopy and disordered local moment calculations, it is demonstrated that the relativistic valence band splitting of the prototypical MnTe altermagnet is of magnetic origin. This is attributed to a novel relativistic spin-splitting phenomenon concurrent with the establishment of the altermagnetic order below the N & eacute;el temperature. image