论文标题
二维各向异性狄拉克材料PTN4C2和PT2N8C6具有量子旋转和山谷大厅效应
Two-dimensional anisotropic Dirac materials PtN4C2 and Pt2N8C6 with quantum spin and valley Hall effects
论文作者
论文摘要
我们提出了两种新型的二维拓扑狄拉克材料，Planar Ptn4c2和Pt2n8c6，它们在Fermi水平上表现出具有线性分散性狄拉克孔状态的石墨烯样电子结构。此外，狄拉克锥体是各向异性的，导致各向异性费米速度，并使实现方向依赖于方向的量子设备成为可能。使用第一原理电子结构计算，我们已经系统地研究了结构，电子和拓扑特性。我们发现自旋轨道耦合打开了相当大的拓扑带隙，因此可以将材料归类为量子自旋大厅绝缘子以及量子谷霍尔霍尔绝缘子。观察到位于连接散装传导和价带的绝缘带间隙中的螺旋边缘状态。我们的工作不仅扩大了Dirac Cone Material家族，而且还为寻找更多二维拓扑量子旋转和Valley Hall绝缘子提供了新的途径。
We propose two novel two-dimensional topological Dirac materials, planar PtN4C2 and Pt2N8C6, which exhibit graphene-like electronic structures with linearly dispersive Dirac-cone states exactly at the Fermi level. Moreover, the Dirac cone is anisotropic, resulting in anisotropic Fermi velocities and making it possible to realize orientation-dependent quantum devices. Using the first-principles electronic structure calculations, we have systemically studied the structural, electronic, and topological properties. We find that spin-orbit coupling opens a sizable topological band gap so that the materials can be classified as quantum spin Hall insulators as well as quantum valley Hall insulators. Helical edge states that reside in the insulating band gap connecting the bulk conduction and valence bands are observed. Our work not only expands the Dirac cone material family, but also provides a new avenue to searching for more two-dimensional topological quantum spin and valley Hall insulators.
