Dutta Debopriya, Oz Annabelle, Hod Oded, Koren Elad
Faculty of Materials Science and Engineering and the Russell Berrie Nanotechnology Institute, Technion - Israel Institute of Technology, 3200003, Haifa, Israel.
Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv, IL, 6997801, Israel.
Nat Commun. 2020 Sep 21;11(1):4746. doi: 10.1038/s41467-020-18597-0.
The unusual electronic properties of edges in graphene-based systems originate from the pseudospinorial character of their electronic wavefunctions associated with their non-trivial topological structure. This is manifested by the appearance of pronounced zero-energy electronic states localized at the material zigzag edges that are expected to have a significant contribution to the interlayer transport in such systems. In this work, we utilize a unique experimental setup and electronic transport calculations to quantitatively distinguish between edge and bulk transport, showing that their relative contribution strongly depends on the angular stacking configuration and interlayer potential. Furthermore, we find that, despite of the strong localization of edge state around the circumference of the contact, edge transport in incommensurate interfaces can dominate up to contact diameters of the order of 2 μm, even in the presence of edge disorder. The intricate interplay between edge and bulk transport contributions revealed in the present study may have profound consequences on practical applications of nanoscale twisted graphene-based electronics.
基于石墨烯的系统中边缘的异常电子特性源于其电子波函数的赝自旋特性，这与它们非平凡的拓扑结构相关。这表现为在材料之字形边缘出现明显的零能量电子态，预计这些态对此类系统中的层间输运有重大贡献。在这项工作中，我们利用独特的实验装置和电子输运计算来定量区分边缘输运和体输运，结果表明它们的相对贡献强烈依赖于角堆叠构型和层间势。此外，我们发现，尽管边缘态在接触周边强烈局域化，但即使存在边缘无序，在非 commensurate 界面中的边缘输运在接触直径达到约 2μm 时仍可能占主导。本研究揭示的边缘输运和体输运贡献之间的复杂相互作用可能对基于纳米级扭曲石墨烯的电子器件的实际应用产生深远影响。
