CAREER: Exploiting Quantum Optoelectronic Properties of Dirac Quasiparticles in Graphene

职业：利用石墨烯中狄拉克准粒子的量子光电特性

• 批准号: 1150719
• 负责人: Xiaodong Xu
• 金额: $ 60万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1150719&HistoricalAwards=false
• 关键词: CAREER; Exploiting; Quantum; Optoelectronic; Properties

**** TECHNICAL ABSTRACT****This project will investigate and enhance understanding of the quantum electronic and optoelectronic phenomena of graphene - a system with two-dimensional Dirac cone dispersion. Graphene has unique electronic and symmetry properties distinct from other 2D electronic systems, such as the chiral massless dispersion of low energy electrons in single-layer graphene, the tunable effective mass and bandgap in bilayer graphene, and unusual quantum Hall effects with large Landau level spacing at moderate magnetic fields. The integration of ultrafast pump-probe spectroscopy with electrical transport will lead to the investigation of the electronic properties of such systems while benefiting from advanced nano-optical spectroscopy techniques. This proposal comprises investigations of both spatial and temporal dynamics of non-equilibrium excitations with and without magnetic fields, the photovoltaic Hall effect with circularly polarized light, Berry-phase related valley Hall effects, broken-symmetry states, and photocurrent generation in the quantum Hall regime. A fundamental understanding of this technologically important material may lead to new applications including high-speed and low power-consumption electronics, broadband communication, new sensing technologies, and photovoltaics. This multidisciplinary research program provides an excellent platform for undergraduate and graduate students to learn physics, device engineering, and materials science, and for post-doctoral researchers to gain professional experience.****NON-TECHNICAL ABSTRACT****As silicon technology faces fundamental limits, breakthroughs in electronics are likely to rely on other materials which allow the exploitation of features and concepts not available in the silicon/oxide system. One promising system is graphene, a single layer of graphite. What sets graphene apart from conventional semiconductors is that the electrons in the graphene behave like photons, traveling with an effective speed just 300 times smaller than the speed of light. This unique feature gives graphene superior physical properties for potential new electronic applications. This project will exploit the novel electronic and optical properties of graphene through a combination of material synthesis, device fabrication, and optoelectronic measurements. In particularly, electron dynamics will be probed by ultrafast laser pulses with a pulse width 13 orders of magnitude smaller than one second. The obtained physical understanding of this technologically important material may lead to high-speed and low power-consumption electronics, broadband communication, new sensing technologies, and photovoltaics. The proposed multidisciplinary research program provides an excellent platform for undergraduate and graduate students to learn physics, device engineering, and materials science, and for post-doctoral researchers to gain professional experience.

*技术摘要*本项目将研究和加深对石墨烯的量子电子和光电子现象的理解，石墨烯是一个具有二维狄拉克锥色散的系统。石墨烯具有不同于其他二维电子系统的独特的电子和对称性，如低能电子在单层石墨烯中的手性无质量色散，在双层石墨烯中的有效质量和带隙可调，以及在中等磁场下具有大朗道能级间距的不寻常的量子霍尔效应。将超快泵浦-探测光谱与电子输运相结合，将有助于研究这类体系的电学性质，同时受益于先进的纳米光学光谱技术。该方案包括研究有磁场和无磁场的非平衡激发的时空动力学，圆偏振光的光伏霍尔效应，与Berry相有关的谷霍尔效应，对称破缺态，以及量子霍尔区中的光电流产生。对这种具有重要技术意义的材料的基本了解可能会导致新的应用，包括高速和低功耗电子产品、宽带通信、新的传感技术和光伏。这一多学科的研究计划为本科生和研究生提供了一个学习物理、设备工程和材料科学的极好平台，并为博士后研究人员获得专业经验提供了一个极好的平台。*非技术摘要*由于硅技术面临根本限制，电子技术的突破可能依赖于其他材料，这些材料允许利用硅/氧化物系统中没有的特征和概念。一个有希望的系统是石墨烯，一种单层石墨层。石墨烯与传统半导体的不同之处在于，石墨烯中的电子行为像光子，有效速度仅比光速小300倍。这一独特的功能使石墨烯具有优异的物理性能，可用于潜在的新电子应用。该项目将通过材料合成、器件制造和光电子测量相结合的方式来开发石墨烯的新的电子和光学性质。特别是，电子动力学将由脉冲宽度小于一秒13个数量级的超快激光脉冲来探测。对这种具有重要技术意义的材料的物理理解可能会导致高速和低功耗的电子产品、宽带通信、新的传感技术和光伏。拟议的多学科研究计划为本科生和研究生提供了一个学习物理、设备工程和材料科学的极好平台，并为博士后研究人员获得专业经验提供了一个极好的平台。