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, α−MnTe. Employing temperature‐dependent angle‐resolved photoelectron spectroscopy across the AM phase transition, we elucidate the emergence of a relativistic valence band splitting concurrent with the establishment of magnetic order. 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 α−MnTe as the temperature decreases. This sheds light on a previously unexplored facet of this intriguing material.This article is protected by copyright. All rights reserved

中文翻译：

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交变磁相变引起的相对论价带分裂的温度依赖性

交变磁（AM）材料表现出非相对论、动量依赖的自旋分裂态，为自旋电子器件带来了新的机遇。虽然自旋分裂的特征是在非相对论性自旋群对称性的框架内记录的，但对相对论性对称性的包含及其对能带结构中新型自旋分裂的出现的影响的探索有限。这项研究深入研究了 AM 材料 α−MnTe 的复杂相对论电子结构。在整个 AM 相变中采用温度依赖性角分辨光电子能谱，我们阐明了相对论价带分裂与磁序建立同时发生的现象。这一发现通过无序局部矩计算得到验证，模拟磁序对电子结构的影响并确认观察到的分裂的磁起源。这种与温度相关的分裂归因于相对论性自旋分裂的出现，这是由于随着温度降低，α−MnTe 中的 AM 有序性增强而导致的。这揭示了这一有趣材料以前未探索过的方面。本文受版权保护。版权所有