论文标题
电场引起的拓扑相变和二维铁磁半导体中自旋轨道耦合和居里温度的大量增强
Electric field induced topological phase transition and large enhancements of spin-orbit coupling and Curie temperature in two-dimensional ferromagnetic semiconductors
论文作者
论文摘要
通过应用电场来调整材料的拓扑和磁性特性，被广泛用于旋转基质中。在这项工作中，我们发现在MNBI $ _2 $ _2 $ _4 $ _4 $单层中，在外部电场上从拓扑上的微不足道到非平凡状态的拓扑相过渡，这是一种拓扑琐碎的铁磁性半导体。结果表明，当电场从0增加到0.15 v/a时，磁各向异性能（MAE）从约0.1 MeV增加到6.3 MeV，而Curie温度TC从13升高到约61 k。MAE的增加主要来自增强的由于施加的电场而增强的自旋轨道耦合。可以从增强的$ p $ - $ d $杂交中理解增强的TC，并减少Te原子的$ P $轨道和MN原子的$ D $轨道。此外，我们提出了两种新颖的Janus材料MNBI $ _2 $ SE $ _2 $ _2 $ te $ _2 $和mnbi $ _2 $ _2 $ s $ _2 $ _2 $ _2 $ _2 $单层具有不同的内部电动极化，可以意识到量子异常霍尔效应（qahe）具有Chern Numbers $ C $ C $ $ c $ c $ = 1和$ C $ C $ c $ c $ c $ c $ c $ c $ co = 2，相应地。我们的研究不仅揭示了电场引起的MNBI2TE4单层的外来特性，而且还提出了新型材料，以实现具有电化的铁磁janus半导体中的Qahe。
Tuning topological and magnetic properties of materials by applying an electric field is widely used in spintronics. In this work, we find a topological phase transition from topologically trivial to nontrivial states at an external electric field of about 0.1 V/A in MnBi$_2$Te$_4$ monolayer that is a topologically trivial ferromagnetic semiconductor. It is shown that when electric field increases from 0 to 0.15 V/A, the magnetic anisotropy energy (MAE) increases from about 0.1 to 6.3 meV, and the Curie temperature Tc increases from 13 to about 61 K. The increased MAE mainly comes from the enhanced spin-orbit coupling due to the applied electric field. The enhanced Tc can be understood from the enhanced $p$-$d$ hybridization and decreased energy difference between $p$ orbitals of Te atoms and $d$ orbitals of Mn atoms. Moreover, we propose two novel Janus materials MnBi$_2$Se$_2$Te$_2$ and MnBi$_2$S$_2$Te$_2$ monolayers with different internal electric polarizations, which can realize quantum anomalous Hall effect (QAHE) with Chern numbers $C$=1 and $C$=2, respectively. Our study not only exposes the electric field induced exotic properties of MnBi2Te4 monolayer, but also proposes novel materials to realize QAHE in ferromagnetic Janus semiconductors with electric polarization.
