论文标题
van der waals Mnbi $ _2 $ te $ _4 $/cr $ _2 $ ge $ _2 $ _2 $ te $ _6 $异构结构
Exchange bias in van der Waals MnBi$_2$Te$_4$/Cr$_2$Ge$_2$Te$_6$ heterostructure
论文作者
论文摘要
分层的范德华（VDW）材料MNBI $ _2 $ te $ _4 $是一种固有的磁性拓扑拓扑器，具有各种拓扑阶段，例如量子异常霍尔效应（qahe）和轴心状态。但是，零场和高温qahe都不容易实现。从理论上讲，可以在MNBI2TE4/Ferromagnetic（FM）绝缘子异质结构中引入交换偏置，从而打开了表面状态间隙，从而更容易实现零视野或高温Qahe。在这里，我们报告了范德华MNBI $ _2 $ te $ _4 $/cr $ _2 $ ge $ _2 $ _2 $ te $ _6 $杂质结构中的电气可调交换偏见。交换偏置出现在临界磁场上，并在磁带隙附近达到最大值。此外，交换偏差是由反铁磁（AFM）MNBI $ _2 $ te $ _4 $ layer而不是FM层所经历的。这样的范德华异质结构提供了一个有前途的平台来研究新型的交换偏见效应并探索可能的高温qahe。
The layered van der Waals (vdW) material MnBi$_2$Te$_4$ is an intrinsic magnetic topological insulator with various topological phases such as quantum anomalous Hall effect (QAHE) and axion states. However, both the zero-field and high-temperature QAHE are not easy to realize. It is theoretically proposed that the exchange bias can be introduced in the MnBi2Te4/ferromagnetic (FM) insulator heterostructures and thus opens the surface states gap, making it easier to realize the zero-field or high-temperature QAHE. Here we report the electrically tunable exchange bias in the van der Waals MnBi$_2$Te$_4$/Cr$_2$Ge$_2$Te$_6$ heterostructure. The exchange bias emerges over a critical magnetic field and reaches the maximum value near the magnetic band gap. Moreover, the exchange bias was experienced by the antiferromagnetic (AFM) MnBi$_2$Te$_4$ layer rather than the FM layer. Such van der Waals heterostructure provides a promising platform to study the novel exchange bias effect and explore the possible high-temperature QAHE.
