Transport studies of periodically driven electronic systems

周期性驱动电子系统的输运研究

• 批准号: 2210180
• 负责人: Ramesh Mani
• 金额: $ 38.85万
• 依托单位: Georgia State University Research Foundation, Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2210180&HistoricalAwards=false
• 关键词: Transport; studies; periodically; driven; electronic

Non-technical Description: The personal computer, the world wide web, the cell phone, high-definition television, electronic sensors, and the expected autonomous car and artificial intelligence, help drive the growth of the United States gross domestic product and these growth engines rely heavily upon technological advances made in semiconductor electronic materials. Although associated electronic materials are typically utilized in their natural equilibrium steady states in three dimensions, theoretical studies suggest the possibility of realizing new capability when the constituent electrons in these materials are artificially rearranged, such as confining them only to two-dimensions. This research examines the electronic properties of two-dimensional systems subjected to excitation from low energy light sources in search of predicted physical phenomena, with a view towards potential applications. This research is timely because recent advances in atomically layered materials has greatly expanded both the universe of available materials for such studies and scope of observable new phenomena. This research project is carried out at Georgia State University, one of the universities which serves the most diverse population in the nation. It will involve undergraduate and high school students, including those from historically underrepresented groups and women, and translate their abilities into the pursuit of career paths in the STEM field, by providing them early exposure to a supportive, confidence building, research experience. The project will also help to add underrepresented sections of society to the nation’s science and technology skill base for the electronics, photonics, defense, and wireless communications industries. Technical Description: This research experimentally examines the magnetoelectronic response under low energy steady state photoexcitation of semiconductor heterostructures and 2D atomic-layered materials including mono-layer, bilayer, and twisted bilayer graphene, atomically thin hexagonal boron nitride (h-BN), and possibly transition metal-dichalcogenides. Photo-excited transport under steady state low energy photoexcitation is mostly unexplored in the above-mentioned material systems partly because of the experimental difficulties encountered in simultaneously bringing together high magnetic fields, low temperatures, low energy photoexcitation over a wide band, with good quality samples. The research team consisting of graduate students, undergraduates, and high school students, will build up layered semiconductor devices and 2D atomic-layered crystals by applying electron beam lithography, plasma etch, and metallization; and examine the properties of electrically contacted and non-contacted devices in the presence of a magnetic field under microwave, mm-wave, and terahertz photoexcitation. Here, some specific problems of interest include the study, to measure particle characteristics, of radiation-induced magnetoresistance oscillations and associated zero-resistance states, for electrons and composite fermions, in the parabolic GaAs/AlGaAs and bilayer graphene systems, as well as in the linearly dispersed monolayer graphene system. Another aim is to clarify the dependence of the fundamental field for the radiation induced oscillations for both electrons and composite fermions on the Fermi wave vector in monolayer graphene. In the twisted bilayer graphene system, one aim is to study the velocity renormalization versus the twist angle. In other STEM aspects, there will be outreach to local high school science teachers to expose the students to nanoscience via online lectures/seminars and host such high school students for nanoscience-based laboratory investigations at Georgia State University.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术描述：个人电脑、万维网、手机、高清电视、电子传感器以及预期的自动驾驶汽车和人工智能，有助于推动美国国内生产总值的增长，而这些增长引擎在很大程度上依赖于半导体电子材料的技术进步。虽然相关的电子材料通常在三维的自然平衡稳态中被利用，但理论研究表明，当这些材料中的组成电子被人为地重新排列时，例如将它们限制在二维空间中，就有可能实现新的能力。本研究考察了二维系统在低能量光源激发下的电子特性，以寻找预测的物理现象，并着眼于潜在的应用。这项研究是及时的，因为原子层状材料的最新进展大大扩展了这类研究的可用材料的范围和可观察到的新现象的范围。这个研究项目是在佐治亚州立大学进行的，佐治亚州立大学是美国人口最多样化的大学之一。它将涉及本科生和高中生，包括那些历史上代表性不足的群体和女性，并通过为他们提供早期支持性、建立信心的研究经验，将他们的能力转化为对STEM领域职业道路的追求。该项目还将帮助在电子、光子学、国防和无线通信行业的国家科学技术技能基础上增加社会中代表性不足的部分。技术描述：本研究实验研究了半导体异质结构和二维原子层材料在低能稳态光激发下的磁电子响应，包括单层，双层和扭曲双层石墨烯，原子薄六方氮化硼（h-BN），以及可能的过渡金属-二硫族化合物。在上述材料体系中，稳态低能光激发下的光激发输运大多未被探索，部分原因是在高磁场、低温、低能光激发的同时在宽波段内获得高质量样品遇到了实验困难。由研究生、本科生和高中生组成的研究小组将利用电子束光刻、等离子体蚀刻和金属化技术构建层状半导体器件和二维原子层状晶体；并研究了在微波、毫米波和太赫兹光激发下，电接触和非接触器件在磁场存在下的性能。在这里，一些感兴趣的具体问题包括研究，测量粒子特性，辐射诱导磁阻振荡和相关的零电阻状态，电子和复合费米子，在抛物型GaAs/AlGaAs和双层石墨烯体系中，以及在线性分散单层石墨烯体系中。另一个目的是澄清辐射诱导电子和复合费米子振荡的基本场对单层石墨烯中费米波矢量的依赖。在扭曲双层石墨烯体系中，一个目的是研究速度重整化与扭转角的关系。在其他STEM方面，将与当地高中科学教师联系，通过在线讲座/研讨会向学生介绍纳米科学，并邀请这些高中学生到佐治亚州立大学进行基于纳米科学的实验室研究。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。