Confining electrons in graphene on hexagonal boron nitride

将石墨烯中的电子限制在六方氮化硼上

• 批准号: 173116321
• 负责人: Professor Dr. Christoph Stampfer
• 金额: --
• 依托单位: II. Physikalisches Institut A - Physik der kondensierten Materie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/173116321?language=en
• 关键词: Confining; electrons; graphene; hexagonal; boron

The main goal of this project is to explore different devices schemes for improving the quality of graphene quantum dots well beyond current standards. An enhanced control over the properties, and possibly even over the shape, of quantum dot devices will allow new sophisticate experiments to investigate excited state spectra in the few-carrier regime as well as charge and spin-relaxation times. All the proposed experiments focus on gaining increased device tunability as well as on reducing the influence of disorder potential. More specifically, we are planning two class of experiments, aimed either at directly improving the quality of today most advanced graphene quantum dot devices, or at addressing unsolved issues related to the influence of bulk and edge-roughness disorder. In the first case, we will combine our ultimate dot design with techniques for embedding graphene nanostructures between hexagonal boron nitride (hBN) thin layers, and employ local metallic top-gates to increase the systems tunability. This device concept will be applied in particular for new pulse-gate experiments to investigate relaxation times in graphene quantum dots, but it is expected to be a global strategy to improve the quality of graphene devices in general. The second class of planed experiments aims instead at addressing the more fundamental question of the role of flake-edges in bilayer graphene devices on hBN. In order to do so, we propose a novel "Corbino-like" device scheme, where the edges of the flake can be fully excluded from the current path. With both class of experiments, we expect make a significant contribution to the understanding of the transport properties of single- and bi-layer graphene nanostructures and quantum dot devices.

该项目的主要目标是探索不同的设备方案，以将石墨烯量子点的质量提高到远远超出当前标准。增强对量子点器件的特性甚至形状的控制将允许新的复杂实验来研究少载流子状态下的激发态光谱以及电荷和自旋弛豫时间。所有提出的实验都侧重于提高器件的可调谐性以及减少无序电位的影响。更具体地说，我们正在计划进行两类实验，旨在直接提高当今最先进的石墨烯量子点器件的质量，或者解决与体积和边缘粗糙度无序影响相关的未解决问题。在第一种情况下，我们将最终的点设计与在六方氮化硼（hBN）薄层之间嵌入石墨烯纳米结构的技术相结合，并采用局部金属顶栅来提高系统的可调谐性。该器件概念将特别应用于新的脉冲门实验，以研究石墨烯量子点的弛豫时间，但预计它将成为提高石墨烯器件质量的全球策略。 第二类计划实验旨在解决六方氮化硼双层石墨烯器件中薄片边缘的作用这一更基本的问题。为此，我们提出了一种新颖的“类 Corbino”设备方案，其中薄片的边缘可以完全排除在当前路径之外。 通过这两类实验，我们期望为理解单层和双层石墨烯纳米结构和量子点器件的传输特性做出重大贡献。