Manipulating physical properties using the spin degree of freedom constitutes a major part of modern condensed matter physics and is a key aspect for spintronics devices. Using the newly discovered two-dimensional van der Waals ferromagnetic CrI₃ as a prototype material, we theoretically demonstrated a giant magneto band-structure (GMB) effect whereby a change of magnetization direction significantly modifies the electronic band structure. Our density functional theory calculations and model analysis reveal that rotating the magnetic moment of CrI₃ from out-of-plane to in-plane causes a direct-to-indirect bandgap transition, inducing a magnetic field controlled photoluminescence. Moreover, our results show a significant change of Fermi surface with different magnetization directions, giving rise to giant anisotropic magnetoresistance. Additionally, the spin reorientation is found to modify the topological states. Given that a variety of properties are determined by band structures, our predicted GMB effect in CrI₃ opens a new paradigm for spintronics applications.

中文翻译：

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二维铁磁CrI _3中自旋方向控制的电子能带结构

利用自旋自由度操纵物理性质是现代凝聚态物理的重要组成部分，并且是自旋电子器件的关键方面。使用新发现的二维范德华力铁磁CrI ₃作为原型材料，我们从理论上证明了巨大的磁带结构（GMB）效应，其中磁化方向的变化极大地改变了电子带结构。我们的密度泛函理论计算和模型分析表明，旋转CrI ₃的磁矩从平面外到平面内的光会引起直接到间接的带隙跃迁，从而引起磁场控制的光致发光。此外，我们的结果表明费米表面在不同的磁化方向上发生了显着变化，从而产生了巨大的各向异性磁阻。另外，发现自旋重新取向可以改变拓扑状态。考虑到能带结构决定了各种性质，我们在CrI _3中预测的GMB效应为自旋电子学应用开辟了新的范例。