Ballistic Graphene-based Dirac Devices

基于弹道石墨烯的狄拉克器件

• 批准号: 351503630
• 负责人: Professor Dr. Klaus Richter
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/351503630?language=en
• 关键词: Ballistic; Graphene; based; Dirac; Devices

The recent development of a new generation of high-mobility graphene samples, enabling ballistic propagation of Dirac fermions over distances of many microns, has spurred an impressive renewal of interest in coherent charge transport and interference phenomena in graphene. Since carriers in ballistic graphene exhibit both electronic and wave-optical properties, these novel experimental abilities, together with sophisticated gating techniques, open up the principle possibility to control charge carrier flow and to put in reach true electron optics phenomena for Dirac fermions in graphene. Still, despite this stunning progress decent control of electron wave propagation in graphene is still limited. Building on recent successful cooperation with experimental groups in this field, we hence propose to investigate various electron-optics phenomena in ballistic graphene devices, including aspects of transport and interferometry, of guiding, collimating and trapping Dirac fermions. This includes in particular the following inter-related objectives: We will develop first proofs of concept and devise optimum geometries for graphene-based Michelson and Mach-Zehnder interferometers, in cooperation with the Schönenberger group (Basel), aiming at graphene-based electron interferometry. As one prerequisite of graphene electron optics and interferometry, we invoke uni- and bipolar graphene settings for electric and magnetic field-controlled efficient charge carrier guiding. As an alternative approach to achieve collimated electron beams, we will further consider p-n and p-n-p-based graphene cavities, acting as electron resonators and emitters. We will investigate the possibility to use such cavities to generate highly directional emission of charge carriers, thereby generalizing concepts for light emission from deformed mesoscopic optical cavities. For a quantitative understanding and reliable predictions of such electron-optics effects we will employ advanced quantum transport simulations for large-scale graphene systems, combined with realistic electrostatic device modelling.

新一代高迁移率石墨烯样品的最新发展，使狄拉克费米子的弹道传播超过许多微米的距离，激发了人们对石墨烯中相干电荷传输和干涉现象的兴趣。由于弹道石墨烯中的载流子同时具有电子和波光学性质，这些新的实验能力，加上复杂的门控技术，开辟了控制电荷载流子流动的原理可能性，并为石墨烯中的狄拉克费米子引入真正的电子光学现象。尽管如此，尽管取得了惊人的进展，但对石墨烯中电子波传播的控制仍然有限。基于最近与该领域实验组的成功合作，我们建议研究弹道石墨烯器件中的各种电子光学现象，包括传输和干涉测量，引导，准直和捕获狄拉克费米子的方面。这特别包括以下相互关联的目标：我们将与Schönenberger集团（巴塞尔）合作，为基于石墨烯的Michelson和Mach-Zehnder干涉仪开发第一个概念验证并设计最佳几何形状，旨在实现基于石墨烯的电子干涉测量。作为石墨烯电子光学和干涉测量的一个先决条件，我们调用单极性和双极性石墨烯设置为电场和磁场控制的有效电荷载流子引导。作为实现准直电子束的替代方法，我们将进一步考虑基于p-n和p-n-p的石墨烯腔，用作电子谐振器和发射器。我们将调查的可能性，使用这种腔产生高度定向发射的电荷载流子，从而概括的概念，从变形介观光学腔的光发射。为了定量理解和可靠预测这种电子光学效应，我们将采用先进的量子输运模拟大规模石墨烯系统，结合现实的静电设备建模。