论文标题
在石墨烯纳米骨中揭开和操纵隐藏的对称性
Unveiling and Manipulating Hidden Symmetries in Graphene Nanoribbons
论文作者
论文摘要
扶手椅石墨烯纳米纤维是全碳纳米回路的高度有前途的半导体类别。在这里，我们介绍了从简单模型哈密顿人和$ \ textit {ab initio} $计算的电子结构的新观点。我们专注于宽度$ n = 3p+2 $的一组特定的纳米式，其中$ n $是整个纳米轴轴和$ p $的碳原子的数量是一个正整数。我们证明，这些纳米骨中的能量间隙开口源于以前未识别的隐藏对称性的破坏，这是通过长期跳跃的$π$ - 电子的跳跃和边缘处发生的结构扭曲。可以通过应用平面晶格应变来恢复或操纵这种隐藏的对称性，这可以使连续的势隙调谐，费米水平的狄拉克点的出现以及拓扑量子相变。我们的工作建立了对扶手椅石墨烯纳米式半导体特征的原始解释，并提供了合理设计其电子结构的指南。
Armchair graphene nanoribbons are a highly promising class of semiconductors for all-carbon nanocircuitry. Here, we present a new perspective on their electronic structure from simple model Hamiltonians and $\textit{ab initio}$ calculations. We focus on a specific set of nanoribbons of width $n = 3p+2$, where $n$ is the number of carbon atoms across the nanoribbon axis and $p$ is a positive integer. We demonstrate that the energy-gap opening in these nanoribbons originates from the breaking of a previously unidentified hidden symmetry by long-ranged hopping of $π$-electrons and structural distortions occurring at the edges. This hidden symmetry can be restored or manipulated through the application of in-plane lattice strain, which enables continuous energy-gap tuning, the emergence of Dirac points at the Fermi level, and topological quantum phase transitions. Our work establishes an original interpretation of the semiconducting character of armchair graphene nanoribbons and offers guidelines for rationally designing their electronic structure.
