论文标题
完美的一维手性状态在有偏见的双层石墨烯中
Perfect one-dimensional chiral states in biased twisted bilayer graphene
论文作者
论文摘要
从理论上讲，我们研究了小角度扭曲的双层石墨烯的电子结构，顶层和底层之间具有巨大的潜在不对称性。我们表明，已知出现在三角形AB-BA域边界上的新兴螺旋状态实际上并未形成一个渗透网络，而是它们提供了独立的，完美的一维通道，以三个不同的方向传播。使用Continuum-Model Hamiltonian，我们证明了应用偏置会导致两个定义明确的能量窗口，其中包含稀疏分布的一维通道。可以使用单层石墨烯的相交电子和孔带的两波段模型来理解这些能量窗口的起源。我们还使用紧密结合模型在扭曲的双层石墨烯中实现晶格变形，并讨论晶格松弛对一维通道的影响。
We theoretically study the electronic structure of small-angle twisted bilayer graphene with a large potential asymmetry between the top and bottom layers. We show that the emergent helical states known to appear on the triangular AB-BA domain boundary do not actually form a percolating network, but instead they provide independent, perfect one-dimensional channels propagating in three different directions. Using the continuum-model Hamiltonian, we demonstrate that an applied bias causes two well-defined energy windows which contain sparsely distributed one-dimensional channels. The origin of these energy windows can be understood using a two-band model of the intersecting electron and hole bands of single layer graphene. We also use the tight-binding model to implement the lattice deformations in twisted bilayer graphene, and discuss the effect of lattice relaxation on the one-dimensional channels.
