Large Fluctuations in Systems Lacking Time-reversal Symmetry

缺乏时间反转对称性的系统中的大波动

• 批准号: 0071059
• 负责人: Mark Dykman
• 金额: $ 17.1万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0071059&HistoricalAwards=false
• 关键词: Large; Fluctuations; Systems; Lacking; Time

0071059Dykman Large fluctuations give rise to many important physical phenomena, from radioactive decay to nucleation in phase transitions and to protein folding. The goal of the proposed research is to develop appropriate mathematical tools and investigate large quantum and classical fluctuations in systems which lack time-reversal symmetry. The problems of specific interest are single- and many-electron tunneling in a magnetic field, including tunneling from correlated two-dimensional electron systems, and escape from a metastable state of nonequilibrium classical and quantum systems, including systems driven by periodic fields. Breaking of time-reversal symmetry results in the occurrence of singularities in the pattern of optimal fluctuational paths. The singularities are expected to have common features in classical and quantum systems. Revealing these features is necessary for evaluating fluctuation probabilities and finding efficient ways of controlling them by external fields. Theoretical results will be compared with experimental data. The goal of the research is to develop theoretical methods of the analysis of large fluctuations in quantum and classical systems lacking time-reversal symmetry, and to investigate related newphysical effects. Although the research is fundamental, its results bear on several applications. It is immediately related to using large fluctuations as a diagnostic tool and controlling fluctuationprobabilities. Concurrent interest and growing body of experimental work on large fluctuations in different areas of physics, chemistry, and biology make the project particularly timely.

大的波动会引起许多重要的物理现象，从放射性衰变到相变中的成核，再到蛋白质折叠。这项拟议的研究的目标是开发适当的数学工具，并研究缺乏时间反转对称性的系统中的大量子和经典涨落。特别令人感兴趣的问题是磁场中的单电子和多电子隧穿，包括从关联的二维电子系统隧穿，以及从非平衡经典和量子系统的亚稳态逃逸，包括由周期场驱动的系统。时间反转对称性的破缺导致最佳涨落路径模式中出现奇点。奇点有望在经典系统和量子系统中具有共同的特征。揭示这些特征对于评估涨落概率和寻找有效的外场控制方法是必要的。将理论结果与实验数据进行比较。这项研究的目的是发展分析缺乏时间反转对称性的量子和经典系统中大涨落的理论方法，并研究相关的新物理效应。尽管这项研究是基础性的，但它的结果涉及到几个应用。它与使用大波动作为诊断工具和控制波动概率直接相关。同时人们对物理、化学和生物学不同领域的大波动的实验工作感兴趣，并不断增加，这使得这个项目特别及时。