CAREER: Developing Graphene Superlattices in a Massive-Massless Hybrid Electron System

职业：在大质量-无质量混合电子系统中开发石墨烯超晶格

• 批准号: 1454950
• 负责人: Cheng Cen
• 金额: $ 50.05万
• 依托单位: West Virginia University Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1454950&HistoricalAwards=false
• 关键词: CAREER; Developing; Graphene; Superlattices; Massive

Nontechnical Description: The ability to control the electronic properties of graphene (an atomic layer of carbon) with nanoscale precision is critical for the implementation of graphene-based devices. However, many existing techniques used in traditional semiconductors are much less effective on graphene due to its unique structure. To address this challenge, a fundamental materials study enabling such precision control in graphene is developed in this CAREER award project. Overlapping an artificial periodic electronic structure on top of graphene has been predicted to be an effective approach for such a task. Stemming from a hybrid bilayer system that integrates graphene with complex oxide interfaces, this project focuses on understanding the controlling mechanisms which could lead to an on-demand tuning technique for future innovative graphene-based electronic devices. Taking advantage of the novel technique developed through this research, the project will produce a new class module on "physics in nanoelectronics" with demonstrations and experimental opportunities for students involved. The associated videos and course materials will be shared with the broader education community. Undergraduate students will be involved in both the research project and the development of the class module. In addition the course module and related materials will be adopted by outreach programs tailored for students from underrepresented groups to promote their interest in physics and a future career in science. Technical Description: The research goal of this CAREER award is to develop a method of band engineering in graphene, which will support the design of unconventional superlattice-based graphene electronics, and to study its fundamental mechanism. The study is based on both the hybrid bilayer system integrating graphene with LaAlO3(LAO)/SrTiO3(STO) interfaces and the conducting atomic force microscopy (c-AFM) technique. The nanoscale periodic patterns of a two dimensional electron gas (2DEG) reversibly created at the LAO/STO interface using c-AFM are expected to generate reprogrammable superlattice potentials in graphene for desired band modifications. The interactions between the massive regular fermions confined at the LaAlO3/SrTiO3 interfaces and the massless Dirac fermions in graphene are studied. Controlling the proximity effects in graphene/complex oxide heterostructures is expected to give rise to exciting new physics and novel functionalities. In addition, the close coupling between oxides and a high-mobility graphene layer could be very powerful for probing the properties at the oxide interfaces, such as sub-band structures and electron correlations. These studies may help to shed light on some of the unsolved problems in complex oxides.

非技术描述：控制石墨烯（碳原子层）具有纳米级精度的能力对于实施基于石墨烯的设备至关重要。但是，由于传统半导体中使用的许多现有技术，由于其独特的结构，因此在石墨烯上的效率要差得多。为了应对这一挑战，该职业奖项项目中开发了一项基本材料研究，从而在石墨烯中开发了这种精确控制。预计将人工周期性电子结构重叠在石墨烯之上是该任务的有效方法。该项目源于将石墨烯与复杂的氧化物界面集成的混合双层系统，该项目着重于理解控制机制，这可能导致对未来创新石墨烯基于电子设备的按需调谐技术。利用通过这项研究开发的新技术，该项目将为“纳米电子物理学”生成一个新的类模块，并为参与的学生提供示范和实验机会。相关的视频和课程材料将与更广泛的教育社区共享。本科生将参与研究项目和班级模块的发展。此外，该课程模块和相关材料将由针对来自代表性不足小组的学生量身定制的外展计划来促进他们对物理学的兴趣和未来的科学职业。技术描述：该职业生涯奖的研究目标是在石墨烯中开发一种乐队工程方法，该方法将支持基于超晶格的石墨烯电子产品的设计，并研究其基本机制。该研究基于将石墨烯与LAALO3（LAO）/SRTIO3（STO）接口和导电原子力显微镜（C-AFM）技术集成的混合双层系统。在LAO/STO界面上使用C-AFM可逆创建的二维电子气体（2DEG）的纳米级周期模式有望在石墨烯中生成可重编程的超晶格电位，以进行所需的频带修饰。研究了限制在LAALO3/SRTIO3界面与石墨烯中的无质量Dirac Fermions之间的大规模规则费物之间的相互作用。预计控制石墨烯/复杂氧化物异质结构中的接近效应将产生令人兴奋的新物理和新功能。另外，氧化物和高弹性石墨烯层之间的紧密耦合对于探测氧化物界面处的性能，例如子频段结构和电子相关性。这些研究可能有助于阐明复杂氧化物中的一些未解决的问题。