Strain-engineering of altermagnetic α-MnTe thin films

Recently, a fundamentally new class of collinear magnetism has emerged, altermagnetism, which breaks time-reversal symmetry like ferromagnetism leading to finite momentum-dependent spin splitting while exhibiting no net magnetization like antiferromagnetism. It has been proposed that promising spintronic applications of such altermagnets are based on the generation and detection of spin currents. For such applications, altermagnetic thin film samples and thus the understanding of strain and finite size effects are mandatory. Following our recent very successful experiment at ID32 on the prototypical altermagnet MnTe demonstrating the momentum-dependent chirality of magnetic excitations in altermagnetism for the first time, we aim to investigate magnetic excitations in strained MnTe thin films using circular-dichroism resonant inelastic X-ray scattering to investigate the recently theoretically proposed giant strain-induced spin splitting in MnTe.

近年来，一类全新的共线磁性分支——交替磁性（altermagnetism）应运而生。这类磁性体系与铁磁性类似，可打破时间反演对称性，产生依赖于动量的有限自旋劈裂；同时又与反铁磁性一致，不存在净磁化强度。已有研究指出，此类交替磁性材料在基于自旋流产生与探测的自旋电子学领域具有可观的应用前景。要实现这类应用，获取交替磁性薄膜样品并厘清其应变与有限尺寸效应是必不可少的前置条件。此前，我们在ID32光束线开展的实验首次观测到了交替磁性体系中磁激发的动量相关手性，取得了圆满成功。本次研究计划借助圆二色共振非弹性X射线散射，对应变碲化锰（MnTe）薄膜的磁激发展开研究，以验证近期理论工作提出的碲化锰中存在的巨大应变诱导自旋劈裂效应。