Quantum Control of Electron-Hole Wave Packets in Semiconductor Nanostructures with Strong Terahertz Pulses

强太赫兹脉冲对半导体纳米结构中电子空穴波包的量子控制

• 批准号: 1063632
• 负责人: Yun-Shik Lee
• 金额: $ 33万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1063632&HistoricalAwards=false
• 关键词: Quantum; Control; Electron; Hole; Wave

****Technical Abstract****This research addresses a fundamental question of light-matter interactions in condensed matter: How do quantum states in semiconductors evolve in the presence of strong electromagnetic waves? Quantum dynamics of intraband transitions (low-energy excitations of 1-10 meV) in semiconductors are little explored to date; the objective of this project is to establish concrete physical pictures of how the quantum dynamics unfold in a many-electron system. Interacting with electron-hole (e-h) wave packets in semiconductor nanostructures, strong terahertz (THz) pulses induce intraband transitions occurring on a picosecond time scale. Ultrafast optical/THz probe pulses resolve not only the amplitude but also the phase of the quantum states in the time domain so that the quantum dynamics can be completely mapped out. Given that Coulomb interactions govern the quantum dynamics, the time-resolved THz study will provide a novel opportunity to understand Coulomb correlations in the e-h system and decoherence of many-body excitations. As the THz intensity exceeds a certain level, the nature of light-matter interactions will undergo a qualitative transition showing traits of the field-induced motion of electrons and holes. This will set a unique stage to observe the quantum-to-classical transition of light-matter interactions in condensed matter. The outreach programs include optics demonstrations for K-12 students, research experience for high school students, and professional development opportunity for science and math teachers.****Nontechnical Abstract****Terahertz (THz) waves are electromagnetic waves whose frequencies lie between the microwave and infrared regions. Naturally occurring THz radiation fills up the space of everyday life providing warmth, yet this part of the electromagnetic spectrum remains the least explored region. THz science and technology is a new and exciting frontier with a broad range of applications. For example, the unique and advanced techniques of THz spectroscopy have been proved to be a powerful tool to investigate the material properties inaccessible until recently. Interacting with a semiconductor, light can create oppositely charged particles, called electrons and holes. When the optical transition occurs near the energy band gap, the attractive interaction between the charged particles leads to the formation of a hydrogen-like system of an electron-hole pair. THz waves strongly interact with the electron-hole pair in semiconductors, because the hydrogen-like system is resonant at THz frequencies. The THz interaction can induce peculiar quantum dynamics of the electron-hole pair in semiconductor nanostructures. The resulting quantum dynamics and associated optical effects are of great interest because the fundamental physical processes have broad applications for ultrahigh-speed optoelectronic devices beyond 100 GHz. The outreach programs include optics demonstrations for K-12 students, research experience for high school students, and professional development opportunity for science and math teachers.

****技术摘要****这项研究解决了凝结物质中光 - 物质相互作用的基本问题：在存在强电磁波的情况下，半导体中的量子状态如何发展？迄今为止，几乎没有探索半导体中标记过渡的量子动力学（1-10 MeV的低能激发）。该项目的目的是建立量子动力学如何在多电子系统中展开的具体物理图片。与半导体纳米结构中的电子孔（E-H）波数据包相互作用，强烈的Terahertz（THZ）脉冲会诱导在Picsecond Time尺度上发生的内标跃迁。超快光学/THZ探针脉冲不仅可以解决幅度，还可以解决时域中量子状态的相位，从而可以完全映射量子动力学。鉴于库仑相互作用控制了量子动力学，时间分辨的THZ研究将为了解E-H系统中的库仑相关性和多体激发的变形提供新的机会。随着THZ强度超过一定水平，光结合相互作用的性质将经历定性的过渡，显示了电子和孔的场诱导运动的特征。这将设定一个独特的阶段，以观察冷凝物质中光 - 物质相互作用的量子到古典跃迁。外展计划包括针对K-12学生的光学演示，高中生的研究经验以及科学和数学老师的专业发展机会。天然发生的THZ辐射填补了日常生活的空间，提供了温暖，但是电磁频谱的这一部分仍然是最不受欢迎的区域。 THZ Science和Technology是一个新的令人兴奋的领域，具有广泛的应用。例如，THZ光谱的独特和先进技术已被证明是研究材料属性直到最近无法访问的强大工具。与半导体相互作用，光可以产生相反电荷的颗粒，称为电子和孔。当光学跃迁发生在能带隙附近时，带电颗粒之间的有吸引力的相互作用会导致形成电子孔对的氢样系统。 THz波与半导体中的电子孔对强烈相互作用，因为氢样系统在Thz频率下具有谐振。 THZ相互作用可以诱导半导体纳米结构中电子孔对的特殊量子动力学。最终产生的量子动力学和相关的光学效应引起了人们的极大兴趣，因为基本的物理过程对超过100 GHz以上的超速光电设备有广泛的应用。外展计划包括针对K-12学生的光学演示，高中生的研究经验以及科学和数学老师的专业发展机会。