Spin direction controlled electronic band structure in two dimensional ferromagnetic materials

Manipulating physical properties using the spin degree of freedom constitutes a major part of modern condensed matter physics and is very important 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 that a change of magnetization direction significantly modifies electronic band structure. Our density functional theory calculations and model analysis reveal that reorienting 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. Our results also show a significant change of Fermi surface with different magnetization directions, leading to giant anisotropic magnetoresistance. What is more, 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. [1][1] P. Jiang, L. Li, Z. Liao, Y. X. Zhao, and Z. Zhong, Nano Letters 18, 3844 (2018)