论文标题
扭曲的双层WSE $ _2 $中的非线性厅效应
Nonlinear Hall Effects in Strained Twisted Bilayer WSe$_2$
论文作者
论文摘要
最近，有人指出，双层WSE $ _2 $的扭曲将在费米能源（Fermi Energy）附近产生拓扑上的非平凡的平坦乐队。在这项工作中，我们表明，由于平面带的非平凡的浆果曲率，带有单轴应变的扭曲的双层WSE WSE $ _2 $（TWSE $ _2 $）具有大型非线性厅（NLH）响应。此外，NLH效应在拓扑相变点附近大大增强，该拓扑相变点可以通过垂直位移场来调节。重要的是，非线性霍尔信号在整个拓扑相过渡点上变化符号，并提供了一种识别拓扑相变的方法，并探测了平谱带的拓扑特性。 NLH效应在拓扑相转换点附近的强大增强性和高可调性使Twse $ _2 $和相关的Moire Materials新平台用于整流和第二次谐波一代。
Recently, it has been pointed out that the twisting of bilayer WSe$_2$ would generate topologically non-trivial flat bands near the Fermi energy. In this work, we show that twisted bilayer WSe$_2$ (tWSe$_2$) with uniaxial strain exhibits a large nonlinear Hall (NLH) response due to the non-trivial Berry curvatures of the flat bands. Moreover, the NLH effect is greatly enhanced near the topological phase transition point which can be tuned by a vertical displacement field. Importantly, the nonlinear Hall signal changes sign across the topological phase transition point and provides a way to identify the topological phase transition and probe the topological properties of the flat bands. The strong enhancement and high tunability of the NLH effect near the topological phase transition point renders tWSe$_2$ and related moire materials new platforms for rectification and second harmonic generations.
