CAREER: Spin and Spin Coherence Dynamics in One- Dimensional Semiconductor Nanostructures

摘要：本学院职业项目通过实验探索了一维（1D）中独特和新颖的自旋依赖现象。这是自旋电子学领域一个引人入胜的新研究方向，代表了电子学的新范式，利用电子自旋而不是电荷来实现设备功能。由于一维凝聚态半导体系统具有独特的结构和电子特性，如自旋-电荷分离，因此在一维凝聚态半导体系统中出现了许多新的与自旋相关的基础物理。为了实现这些目标，化学合成具有可调谐结构和物理性质的II-VI族和III-V族一维半导体纳米结构将被应用于一维模型系统。超快光学自旋共振技术将用于研究合成一维纳米结构中自旋动力学的时空演化。从实用的角度来看，基于自旋自由度，一维凝聚态体系代表了可用于有效信息传输的最小维结构。最终，该项目的结果将对纳米自旋电子技术的功能和集成至关重要，并导致量子信息处理和量子计算的进步。除了为研究生提供直接培训外，该项目的一个重要组成部分是将研究与本科教育计划相结合。这将涉及开发一门新的本科课程，旨在让有动力的本科生在他们大学生涯的早期参与纳米科学的独立研究，并作为一个平台，将他们从传统课程中学到的知识转化为研究经验。本课程也将填补马里兰大学最近开设的纳米科学与技术跨学科辅修课程的本科生研究机会的需要。技术摘要：本学院职业项目的目标是利用全光远场和近场自旋共振技术，发展基于实验的一维（1D）凝聚态半导体系统中自旋和自旋相干动力学的基本理解。由于实际一维半导体系统具有独特的自旋-自旋和自旋-电荷相互作用以及自旋与耗散环境的耦合，许多奇异的自旋相关物理已经被预测。本项目将化学合成具有可控结构和物理性质的II-VI族和III-V族一维半导体纳米结构作为一维模型系统，并结合所有光学自旋共振技术来探测纳米结构内部的自旋动力学。几个基本问题将集中讨论，包括自旋相干寿命、电子和激子朗德g因子、本征自旋弛豫机制、维数和各向异性效应、一维自旋扩散和自旋相干输运、一维纳米结构中的相干光-物质-自旋相互作用和一维纳米腔中的自旋凝聚过程。一维凝聚态体系也代表了基于自旋自由度的最小维结构，可以用于有效的信息传输。最终，这些研究将对纳米自旋电子技术的功能和集成至关重要。除了为研究生提供直接培训外，该项目的一个重要组成部分是将研究与本科教育计划相结合。这将涉及开发一门新的本科课程，旨在让有动力的本科生在他们的大学生涯早期参与纳米物理学和纳米材料科学的独立研究，并作为一个平台，将他们从传统课程中学到的知识转化为研究经验。

Non-Technical Abstract:This Faculty Career project experimentally explores unique and novel spin dependent phenomena in one dimension (1D). This is a fascinating new research direction in the field of Spintronics that represents a new paradigm of electronics and utilizes electron spin rather than charge for device functionality. There are many exotic new spin- related fundamental physics in 1D condensed matter semiconductor systems due to their unusual structural and electronic properties, such as spin-charge separation. To achieve these, chemically synthesized Group II-VI and III-V 1D semiconductor nanostructures with tunable structural and physical properties will be applied as 1D model systems. The state-of-the-art ultrafast optical spin resonance techniques will be employed to investigate the spatial and temporal evolutions of spin dynamics in as-synthesized 1D nanostructures. From the practical point of view, 1D condensed matter systems represent the smallest dimension structures that can be used for efficient information transport based on the spin degree of freedom. Ultimately, results from this project will be critical to the function and integration of NanoSpintronic technology and lead to the advance in quantum information processing and quantum computation. An important component of this project, in addition to direct training provided to graduated students, is the integration of research with undergraduate education program. This will involve developing a new undergraduate course, aiming at exposing motivated undergraduate students to independent research in nanoscience early in their college careers and serving as a platform to transform their knowledge learnt from traditional course to research experience. This course will also fill the need for research opportunities for undergraduates in the recently initiated Interdisciplinary Minor Program in Nanoscale Science and Technology in the University of Maryland. Technical Abstract:The object of this Faculty Career project is to develop fundamental experimentally based understanding of spin and spin coherence dynamics in one-dimensional (1D) condensed matter semiconductor systems with all-optical far-field and near-field spin resonance techniques. Many exotic new spin- related physics have been predicted for real 1D semiconductor systems due to their unique spin-spin and spin-charge interactions as well as spin couplings with their dissipate environment. In this project chemically synthesized Group II-VI and III-V 1D semiconductor nanostructures with controllable structural and physical properties will be applied as 1D model systems and combined with all optical spin resonance techniques to probe spin dynamics within nanostructures. Several fundamental issues will be focused on, including spin coherence lifetimes, electron and exciton Lande g-factors, intrinsic spin relaxation mechanisms, dimensionality and anisotropic effects, 1D spin diffusion and spin coherence transport, coherent light-matter-spin interactions within 1D nanostructures and spin condensate process in 1D nanocavity. 1D condensed matter systems also represent the smallest dimension structures that can be used for efficient information transport based on the spin degree of freedom. Ultimately, these studies will be critical to the function and integration of NanoSpintronic technology. An important component of this project, in addition to direct training provided to graduated students, is the integration of research with undergraduate education program. This will involve developing a new undergraduate course, aiming at exposing motivated undergraduate students to independent research in nanophysics and nanomaterial sciences early in their college careers and serving as a platform to transform their knowledge learnt from traditional course to research experience.