Fluctuation Phenomena and Measurement Theory in Mesoscopic Electronic and Optical Systems

介观电子和光学系统中的涨落现象和测量理论

• 批准号: 0408638
• 负责人: Alfred Stone
• 金额: --
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2008-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0408638&HistoricalAwards=false
• 关键词: Fluctuation; Phenomena; Measurement; Theory; Mesoscopic

This theoretical research has two different focus areas: nanoelectronic devices for ultrasensitive detection and amplification, and microcavity resonators and lasers, typically on the size scale of 10-100 microns.The electronic aspect of the project will analyze the conditions under which a mesoscopic detector achieves quantum-limited detection, which refers to a measurement with the minimum degree of backaction on the measured quantum system allowed by the uncertainty principle. Such questions are of relevance in quantum information physics where the measured quantum system would be a quantum bit and the detector is the read-out device. The same condition determines the minimum noise associated with any quantum system that acts as an amplifier due to the presence of zero point fluctuations. Earlier work analyzing mesoscopic scattering detectors without electron-electron interactions found a simple condition for reaching the quantum limit which can be expressed information-theoretically: There should be no information about the measured system imprinted in the input variable to the detector which is not extracted by measuring the output variable. In the current project the quantum limit condition will be analyzed for interacting detectors, specifically mesoscopic scattering detectors (resonant tunneling structures) in the presence of dephasing, and semiconducting quantum dots near the charge degeneracy points. It is hoped that general information-theoretic principles will also be developed to understand qualitatively the approach to the quantum limit of detection in wider classes of quantum amplifiers such as metallic and superconducting single-electron transistors and superconducting quantum interference devices.The optics aspect of the project treats dielectric microcavity resonators and lasers, which, due to their asymmetric shape, generate complex, and at least partially chaotic, ray dynamics. Despite the presence of ray chaos, such resonators have high-Q resonances with directional emission, making them potentially useful for integrated optical devices when compared to standard whispering gallery resonators with circular symmetry. The project will analyze the predicted enhancement of the rate of evanescent leakage (tunneling of photons) out of such high-Q resonances due to the effect of ray chaos. It will also analyze the mode-locking behavior, which is expected to occur in the non-linear regime of such resonators, specifically focusing on the case of stable orbit multiplets which can be calculated analytically. A more general theory of lasing in such complex resonators will be developed with the aim of understanding mode competition and the enormous increase in output power such lasers display in comparison to microcylinder lasers. The photon statistics of such resonators and lasers is predicted to be very different from conventional lasers and will be studied in detail during this project with the goal of proposing novel and interesting experiments.Both of these focus areas of research have a broader impact on current science and technology. The properties of quantum amplifiers have become of great importance in the field of quantum information physics and quantum computation. As is now well known, quantum information processors are predicted to have revolutionary properties such as an exponential speed-up of factoring algorithms for decoding. Solid-state superconducting qubits are a reality and the measuring devices to manipulate them and read them out are being developed worldwide; this has brought the abstract topic of quantum measurement theory into the real world of the physics of nanostructures. This research addresses several important questions in this field.The optics area relates to several problems of current technological interest. First, it relates to the development of integrated optical technology for communication applications; and second it relates to the development of novel blue and ultraviolet semiconductor light sources which will be important for lithographic, sensing, display and data storage applications. Three inventions relating to these areas have been patented based on earlier stages of this research.%%% This theoretical research has two different focus areas: nanoelectronic devices for ultrasensitive detection and amplification, and microcavity resonators and lasers, typically on the size scale of 10-100 microns. With both topics, the research blends fundamental research with possible technological applications. Besides the fundamental nature of the research, the technological applications touch on quantum information systems and novel light sources for application in advanced computers. Both graduate students and postdoctoral associates will participate in the project.***

这种理论研究有两个不同的重点领域：用于超灵敏检测和放大的纳米电子器件，以及微腔谐振器和激光器，通常尺寸为10-100微米。该项目的电子方面将分析介观检测器实现量子限制检测的条件，它是指在测不准原理允许的情况下，对被测量子系统的反作用程度最小的测量。 这些问题在量子信息物理学中是相关的，其中被测量的量子系统将是量子比特，检测器是读出设备。 相同的条件决定了与任何量子系统相关的最小噪声，由于零点波动的存在，量子系统充当放大器。 早期的工作分析介观散射探测器没有电子-电子相互作用，发现了一个简单的条件，达到量子极限，可以表示的信息理论上：不应该有任何信息的测量系统的输入变量印到检测器，这不是通过测量输出变量提取。 在目前的项目中，量子极限条件将分析相互作用的探测器，特别是介观散射探测器（共振隧穿结构）在退相的存在下，和半导体量子点附近的电荷简并点。 希望一般的信息理论原理也将发展到定性地理解方法的量子检测极限在更广泛的类量子放大器，如金属和超导单电子晶体管和超导量子干涉器件。该项目的光学方面对待介电微腔谐振器和激光器，其中，由于它们的不对称形状，产生复杂的，和至少部分混乱的光线动力学。 尽管存在射线混沌，但这种谐振器具有定向发射的高Q谐振，使得它们与具有圆形对称的标准回音壁谐振器相比时潜在地可用于集成光学器件。 该项目将分析由于射线混沌的影响，预计这种高Q共振的倏逝波泄漏（光子隧穿）率会增加。 它还将分析锁模行为，这是预计将发生在非线性制度的这种谐振器，特别是专注于稳定的轨道多重态的情况下，可以分析计算。 一个更一般的理论，在这种复杂的谐振腔中的激光将开发与理解模式竞争和输出功率的巨大增加，这样的激光器显示相比，微柱激光器的目的。 这种谐振器和激光器的光子统计预计将与传统激光器有很大的不同，并将在本项目中进行详细研究，目的是提出新颖有趣的实验。这两个重点研究领域对当前科学和技术都有更广泛的影响。 量子放大器的性质在量子信息物理和量子计算领域中具有重要意义。 众所周知，量子信息处理器预计将具有革命性的特性，例如用于解码的因子分解算法的指数加速。 固态超导量子比特已经成为现实，操纵和读取它们的测量设备正在世界范围内开发;这将量子测量理论的抽象主题带入了纳米结构物理学的真实的世界。 这项研究解决了这一领域的几个重要问题。光学领域涉及到当前技术感兴趣的几个问题。 首先，它涉及到通信应用的集成光学技术的发展;其次，它涉及到新的蓝色和紫外半导体光源的发展，这将是重要的光刻，传感，显示和数据存储应用。 基于这项研究的早期阶段，与这些领域相关的三项发明已获得专利。%这项理论研究有两个不同的重点领域：用于超灵敏检测和放大的纳米电子器件，以及微腔谐振器和激光器，通常尺寸为10-100微米。 对于这两个主题，研究将基础研究与可能的技术应用相结合。 除了研究的基本性质外，技术应用还涉及量子信息系统和用于先进计算机的新型光源。 研究生和博士后都将参与该项目。*