Integrated quantum-dot devices and single-electron dynamics in graphene

利用电子束刻蚀法和反应等离子体刻蚀法，可以在石墨烯表面刻蚀出石墨烯纳米结构。然而，这种纳米结构器件的性能很大程度上取决于样品质量、衬底的影响以及样品边缘的化学性质。因此，我们提出并展示了一种可能的替代器件结构来探测石墨烯纳米结构，该结构可以减少样品边缘的影响并保持狄拉克锥。低温电子输运结果揭示了由均匀垂直磁场和金属/石墨烯结静电表面电位诱导的库仑封锁效应和量子约束的演化。这些实验结果和理论分析表明，狄拉克型粒子被限制在介观石墨素体系中。

Graphene nanostructures can be fabricated by carving out of graphene by using electron-beam lithography and reactive plasma etching process. The performance of such nanostructured devices, however, is expected to depend strongly on the sample quality, influence of the substrate, and the chemical nature of sample edges. Therefore, we propose and show one of the possible alternative device structures to probe the graphene nanostructures that the influence of the sample edges can be reduced and Dirac cones can be maintained. Low temperature electron-transport results revealed the evolution of the Coulomb blockade effect and quantum confinement, which are induced by both a uniform perpendicular magnetic field to the graphene sheets and an electrostatic surface-potential by the metal/graphene junction. These experimental results and theoretical analysis indicate that a Dirac-type particle is confined in our mesoscopic grapheme system.