Collective and Nonlinear Physics of Mesoscopic Oscillators

介观振荡器的集体和非线性物理

• 批准号: 0314069
• 负责人: Michael Cross
• 金额: --
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0314069&HistoricalAwards=false
• 关键词: Collective; Nonlinear; Physics; Mesoscopic; Oscillators

Mechanical oscillations at the sub-micron scale - either fabricated lithographically or built up from the atomic scale as in carbon nanotubes - combine the physics of nonlinearity, noise and dispersion, collective behavior, and ultimately quantum effects, in systems that are both readily investigated experimentally and likely to be important in technology. This project is to study theoretically the nonlinear, nonequilibrium, stochastic, and pattern forming aspects of such oscillators, with strong motivation from the concurrent experimental program at Caltech.Modern lithographic techniques allow the construction of free-standing mechanical oscillators, made from silicon, silicon nitride, gold and other materials, at ever decreasing sizes, and with a wide variety of geometries, from simple beams and cantilevers, to complex multi-oscillator structures that provide isolation from supports. In addition, the fabrication of mechanical oscillators made from single- and multi-walled carbon nanotubes is rapidly developing. These experimental advances open up interesting new avenues of basic physics, which have direct application to possible technological applications of such devices in detectors, communication and other areas.On the one hand the fabrication technologies open up new experimental possibilities, for example the ease of constructing large arrays of oscillators, and the approach to size scales where quantum effects become important. On the other hand, there are new challenges that arise, such as the inevitable dispersion of the oscillator frequencies due to imperfections of the fabrication, the growing importance of stochastic effects from the thermal noise as sizes decrease, and the nonlinearity of the oscillators that will develop at the larger amplitudes of motion that will enhance the signal to noise ratio of detection schemes. These must be understood for the successful development of applications. Thus there is a strong need for a theoretical investigation of such small scale oscillators, combining the issues of nonlinearity, noise and dispersion, collective behavior (pattern formation), and quantum effects. Each of these areas has a large body of theoretical work, of greater or lesser applicability to experiment. The progress in the range of devices that can be fabricated provides strong experimental stimulus for testing, refining and combining these theoretical ideas in a new physical domain. The possibilities of precise measurements of the behavior of large numbers of dynamical components, through on-chip diagnostics and processing, makes mesoscopic oscillators an exciting testbed for these theoretical ideas. In turn the theory may suggest completely new protocols for technological applications, as well as provide new insights on the design of more conventional protocols.Besides being carried out in close coordination with an experimental program at Caltech, the research will involve both graduate students and undergraduate students.%%% Mechanical oscillations at the sub-micron scale - either fabricated lithographically or built up from the atomic scale as in carbon nanotubes - combine the physics of nonlinearity, noise and dispersion, collective behavior, and ultimately quantum effects, in systems that are both readily investigated experimentally and likely to be important in technology. This project is to study theoretically the nonlinear, nonequilibrium, stochastic, and pattern forming aspects of such oscillators, with strong motivation from the concurrent experimental program at Caltech.Besides being carried out in close coordination with an experimental program at Caltech, the research will involve both graduate students and undergraduate students.***

亚微米尺度上的机械振荡——无论是用光刻技术制造的，还是像碳纳米管那样从原子尺度上建立起来的——结合了非线性、噪声和色散、集体行为以及最终的量子效应等物理特性，这些系统既易于实验研究，又可能在技术上很重要。这个项目是在理论上研究这些振荡的非线性、非平衡、随机和模式形成方面，有来自加州理工学院并行实验项目的强烈动机。现代光刻技术允许建造独立的机械振荡器，由硅、氮化硅、金和其他材料制成，尺寸越来越小，具有各种各样的几何形状，从简单的梁和悬臂，到复杂的多振荡器结构，提供与支撑隔离。此外，单壁和多壁碳纳米管机械振荡器的制造也在迅速发展。这些实验进展为基础物理学开辟了有趣的新途径，直接应用于这种装置在探测器、通信和其他领域的可能技术应用。一方面，制造技术开辟了新的实验可能性，例如，构建大型振荡器阵列的便捷性，以及量子效应变得重要的尺寸尺度的方法。另一方面，出现了新的挑战，例如由于制造缺陷导致振荡器频率不可避免的色散，随着尺寸减小，热噪声的随机效应日益重要，以及振荡器的非线性将在较大的运动幅度下发展，这将提高检测方案的信噪比。为了成功地开发应用程序，必须理解这些内容。因此，迫切需要结合非线性、噪声和色散、集体行为（模式形成）和量子效应等问题，对这种小尺度振荡器进行理论研究。这些领域中的每一个都有大量的理论工作，或多或少适用于实验。可制造器件范围的进展为在新的物理领域中测试、改进和结合这些理论思想提供了强大的实验刺激。通过片上诊断和处理，对大量动态元件的行为进行精确测量的可能性，使介观振荡器成为这些理论思想的令人兴奋的试验台。反过来，该理论可能为技术应用提出全新的协议，并为设计更传统的协议提供新的见解。除了与加州理工学院的一个实验项目密切配合外，这项研究还将涉及研究生和本科生。亚微米尺度上的机械振荡——无论是用光刻技术制造的，还是像碳纳米管那样从原子尺度上建立起来的——结合了非线性、噪声和色散、集体行为以及最终的量子效应等物理特性，这些系统既易于实验研究，又可能在技术上很重要。这个项目是在理论上研究这些振荡的非线性、非平衡、随机和模式形成方面，有来自加州理工学院并行实验项目的强烈动机。除了与加州理工学院的一个实验项目密切配合外，这项研究还将涉及研究生和本科生