Institut für Physik, Technische Universität Chemnitz, 09126, Chemnitz, Germany.
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona (Cerdanyola del Vallès), Spain.
Nat Commun. 2018 Oct 24;9(1):4426. doi: 10.1038/s41467-018-06940-5.
High quality graphene nanoribbons epitaxially grown on the sidewalls of silicon carbide (SiC) mesa structures stand as key building blocks for graphene-based nanoelectronics. Such ribbons display 1D single-channel ballistic transport at room temperature with exceptionally long mean free paths. Here, using spatially-resolved two-point probe (2PP) measurements, we selectively access and directly image a range of individual transport modes in sidewall ribbons. The signature of the independently contacted channels is a sequence of quantised conductance plateaus for different probe positions. These result from an interplay between edge magnetism and asymmetric terminations at opposite ribbon edges due to the underlying SiC structure morphology. Our findings demonstrate a precise control of transport through multiple, independent, ballistic tracks in graphene-based devices, opening intriguing pathways for quantum information device concepts.
高质量的石墨烯纳米带在碳化硅（SiC）台面结构的侧壁外延生长，是基于石墨烯的纳米电子学的关键构建模块。这种纳米带在室温下表现出 1D 单通道弹道输运，具有异常长的平均自由程。在这里，我们使用空间分辨的两点探针（2PP）测量，选择性地访问和直接成像侧壁纳米带中的一系列单个传输模式。独立接触通道的特征是，对于不同的探针位置，存在一系列量子化电导平台。这是由于底层 SiC 结构形态导致边缘磁体和相对纳米带边缘的不对称末端之间的相互作用所致。我们的研究结果表明，通过基于石墨烯的器件中的多个独立弹道轨迹，可以精确控制传输，为量子信息器件概念开辟了有趣的途径。
