Terahertz Quantum Electronics of Carbon Nanostructures: Population Inversion, Gain and Coherent Bandgap Engineering

碳纳米结构的太赫兹量子电子学：粒子数反转、增益和相干带隙工程

• 批准号: 1611454
• 负责人: Jigang Wang
• 金额: $ 37.72万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611454&HistoricalAwards=false
• 关键词: Terahertz; Quantum; Electronics; Carbon; Nanostructures

The challenge of pushing the switching speed-limit and integration density of today's logic and modulation devices into the terahertz (one trillion cycles per second) and sub-20 nanometer regime underlies the entire field of information processing, recording and communication. This challenge may be met by a novel paradigm of terahertz quantum nano-electronics based on ultrafast coherent laser pumping in graphene - one atom thick, the honeycomb-shaped carbon material - and single-walled carbon nanotubesthe rolled-up sheets of graphene monolayers. Researchers will use short pulsed terahertz light, outside the visible spectrum, and an ultrafast camera technique to directly monitor the formation and time evolution of photo-excited states in these carbon nanomaterials. This novel method will allow them to capture and control their novel electromagnetic properties on the femtosecond scale, or to one quadrillionth of a second. The results will open fascinating opportunities to demonstrate their significant potential to advance, e.g., above-gigahertz light modulators, broadband gain mediums from the infrared to terahertz, radiation controlled hot-electron transistors, multi-functional devices responding to ultrabroadband electromagnetic radiations from the terahertz to visible frequency. Our success in this "ultrafast" and "ultrasmall" challenge will reveal as-yet-undiscovered physical processes for developing new generation optoelectronic device and offer perspectives for sustaining the information revolution and the 21st century's digital economy. Education is an integral and essential component in this proposal. It consists of interconnected, specific plans for education that span small college professors/undergraduates, "A Physics Day" program for high school teachers and their students; outreach to underrepresented minority students and provision of research/training opportunities to them.How coherent photoexcitations control excitonic bosons in single-walled carbon nanotubes and Dirac fermions in graphene monolayers is among the most fundamental, yet cross-cutting, issues in quantum and optoelectronic technologies. The proposal aims to explore some remarkable laser-driven quantum processes in these carbon nanostructures and demonstrate their significant potential for device applications. The primary goals are: to determine broadband gain spectrum and threshold in strongly photoexcited graphene monolayers; to demonstrate coherently photo-driven, bandgap opening near the Dirac cone using intense terahertz pulses; to investigate extreme mid-infrared and far-infrared nonlinear wave mixing in graphene; to achieve terahertz stimulated emission in single-walled carbon nanotubes using two-photon excited, dark exciton states. The approach for the timely advancement lies in the combination of ultrashort terahertz pulses, specially fabricated, high quality mono- and few-layer graphene and carbon nanotubes, and ultra-broadband probe capability from the terahertz to visible spectral regions. This proposal has identified compelling opportunities to advance one of the most poorly- addressed territories in some most exciting materials today dynamical, non-equilibrium, and nonlinear aspects of carbon nanostructures. The targeting problems are in the boundaries of several frontiers such as quantum optical control of matter, terahertz electrical transport, and ultrafast optoelectronic technology. Although sophisticated theoretical studies have been underway, the experimental schemes for exploring a wide range of the predicted fundamental phenomena, as proposed, have lagged behind. These original results are transformative, opening the possibility for graphene- and carbon nanotube- based above-terahertz speed modulators, saturable absorbers, ultra-broadband gain medium.

将当今逻辑和调制设备的开关速度限制和集成密度推入Terahertz（每秒1万亿个循环）和低于20纳米制度的挑战是整个信息处理，记录和通信的整个领域。基于超快相干激光泵送的Terahertz量子纳米电子电源的新型范式可以应对这一挑战 - 一种原子厚，蜂窝状的碳材料和单壁碳纳米管纳米蛋白蛋白胶质的碳note胶滚动的石墨烯单层滚滚板。研究人员将使用短脉冲的Terahertz光，可见光频谱外部和超快摄像头技术直接监测这些碳纳米材料中光激发状态的形成和时间演变。这种新颖的方法将使他们能够在飞秒尺度上捕获和控制其新颖的电磁特性，或者占一秒钟的四分之一。结果将为展示其前进的巨大潜力，例如高于gigahertz的光调制器，从红外线到terahertz，辐射控制的热电子晶体管，多功能设备，对Terahertz从Terahertz到可见频率响应的多功能设备。我们在这个“超快”和“超大挑战”挑战方面的成功将揭示出尚未发现的物理过程，以开发新一代的光电设备，并为维持信息革命和21世纪的数字经济提供了观点。教育是该提案中不可或缺的组成部分。它由跨越小学教授/本科生的互连，具体的教育计划组成，这是针对高中教师及其学生的“物理日”计划；向代表性不足的少数族裔学生提供宣传，并向他们提供研究/培训机会。如何控制单壁碳纳米管中的激子玻色子和石墨烯单层中的迪拉克·费米子（Dirac Fermions）是最基本的，但最基本的，但在量子和光学技术方面的交叉，问题，却是交叉的，问题。该提案旨在探索这些碳纳米结构中的一些显着激光驱动的量子过程，并证明它们在设备应用中的重要潜力。主要目标是：确定宽带增益光谱和强烈光激发的石墨烯单层中的阈值；为了证明相干照相驱动的，使用强烈的Terahertz脉冲在Dirac锥附近开口的带隙开口；研究石墨烯中极端的中红外和远红外非线性波混合；为了实现Terahertz，使用双光子激发的深色激子状态刺激单壁碳纳米管中的发射。及时进步的方法在于超短型Terahertz脉冲，特殊制造的，高质量的单层石墨烯和碳纳米管以及从Terahertz到可见光谱区域的超大频带探针能力。该提案已经确定了令人信服的机会，可以在当今一些最令人兴奋的材料中推进最糟糕的领土之一，这是碳纳米结构的动力学，非平衡和非线性方面。目标问题在几个边界的边界中，例如物质的量子光学控制，Terahertz电运和超快光电技术。尽管已经进行了复杂的理论研究，但探索广泛的预测基本现象的实验方案已落后。这些原始结果具有变革性，为基于石墨烯和碳纳米管的速度调节剂，可饱和吸收剂，超宽带增益培养基的可能性打开了可能性。