Trainer Daniel J, Srinivasan Srilok, Fisher Brandon L, Zhang Yuan, Pfeiffer Constance R, Hla Saw-Wai, Darancet Pierre, Guisinger Nathan P
Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Department of Physics, Old Dominion University, Norfolk, Virginia 23529, United States.
ACS Nano. 2022 Oct 25;16(10):16085-16090. doi: 10.1021/acsnano.2c04361. Epub 2022 Aug 15.
We synthesize artificial graphene nanoribbons by positioning carbon monoxide molecules on a copper surface to confine its surface state electrons into artificial atoms positioned to emulate the low-energy electronic structure of graphene derivatives. We demonstrate that the dimensionality of artificial graphene can be reduced to one dimension with proper "edge" passivation, with the emergence of an effectively gapped one-dimensional nanoribbon structure. These one-dimensional structures show evidence of topological effects analogous to graphene nanoribbons. Guided by first-principles calculations, we spatially explore robust, zero-dimensional topological states by altering the topological invariants of quasi-one-dimensional artificial graphene nanostructures. The robustness and flexibility of our platform allow us to toggle the topological invariants between trivial and nontrivial on the same nanostructure. Ultimately, we spatially manipulate the states to understand fundamental coupling between adjacent topological states that are finely engineered and simulate complex Hamiltonians.
我们通过将一氧化碳分子置于铜表面，把其表面态电子限制在人工原子中，这些人工原子的位置被设定为模拟石墨烯衍生物的低能电子结构，从而合成了人工石墨烯纳米带。我们证明，通过适当的“边缘”钝化，人工石墨烯的维度可以降至一维，同时会出现有效的带隙一维纳米带结构。这些一维结构显示出与石墨烯纳米带类似的拓扑效应证据。在第一性原理计算的指导下，我们通过改变准一维人工石墨烯纳米结构的拓扑不变量，在空间上探索稳健的零维拓扑态。我们平台的稳健性和灵活性使我们能够在同一纳米结构上在平凡和非平凡的拓扑不变量之间切换。最终，我们在空间上操纵这些态，以理解精细设计的相邻拓扑态之间的基本耦合，并模拟复杂的哈密顿量。
