论文标题
过渡金属二甲基元素Janus单层中的可调拓扑和浆果曲率偶极子
Tunable Topology and Berry Curvature Dipole in Transition Metal Dichalcogenide Janus Monolayers
论文作者
论文摘要
Janus过渡金属二分法源具有内在的镜子不对称性，具有广泛的有趣特性。在这项工作中，我们使用第一原理和紧密结合计算来研究Janus单层$ _2 $。我们发现WSETE和WSTE在拓扑上是微不足道的，与父母量子旋转厅绝缘子WTE $ _2 $相反。由于对非线性霍尔效应的兴趣日益增加，这也需要不对称结构，我们研究了浆果曲率及其在这些Janus系统中的偶极子，发现它们尽管处于拓扑琐碎的阶段，但它们表现出了巨大的浆果曲率偶极子的值。我们追踪这种行为的起源，并提出一个低能的大型迪拉克模型，以了解我们从头算计算的主要特征。我们的预测介绍了Janus单层作为探索和工程非线性大厅效应的有前途的新平台。
Janus transition metal dichalcogenides, with intrinsic mirror asymmetry, exhibit a wide array of interesting properties. In this work, we study Janus monolayers derived from WTe$_2$ using first-principles and tight-binding calculations. We discover that WSeTe and WSTe are topologically trivial, in contrast to the parent quantum spin Hall insulator WTe$_2$. Motivated by the growing interest in non-linear Hall effect, which also requires asymmetric structures, we investigate the Berry curvature and its dipole in these Janus systems and find that they exhibit strikingly large values of Berry curvature dipole, despite being in the topologically trivial phase. We track down the origin of this behaviour and put forth a low-energy massive Dirac model to understand the central features of our ab initio computations. Our predictions introduce Janus monolayers as promising new platforms for exploring as well as engineering non-linear Hall effect.
