Nonequilibrium Statistical Mechanics of Nanoscale Systems

该奖项由材料研究部和化学部资助。它支持与小系统的非平衡行为相关的理论研究和教育，从生物分子复合物到人工分子机器。 这项研究的主要目的是促进对热力学定律的基本理解，以及它们如何应用于纳米系统，其中波动是重要的和不可避免的。 PI的方法将包括对易处理模型的精确分析，对实验研究系统的理论和数值建模，以及一般原理的制定。 需要解决的两个中心问题是：1）统计热力学对分子水平系统的信息处理施加了什么基本约束？2)人造分子机器的定向运动可以通过宏观外部参数的变化来产生和控制的原理是什么？第一个问题是由生物分子系统确实执行信息处理任务的现实和人工分子机器开始显示这种能力引起的。 PI将开发模型，捕获自主分子系统信息处理的基本特征，同时保持精确分析或数值模拟。 通过揭示明确的，透明的运作机制，这样的模型将提供简单的范例，调查的热力学信息处理的情况下，热波动dominated.Research在第二个问题的研究最初是由实验涉及操纵环状分子，catenanes，由外部刺激的变化。我们的目标是一个系统的控制理论，在大量的热噪声的存在下，人工分子机器。 PI将在随机泵的一般理论框架内处理这个问题，在随机泵中，系统在离散状态网络之间进行随机转换，转换率随时间变化。 网络拓扑结构在分析中起着重要的作用。该奖项支持研究生和博士后在理论和计算统计力学方法方面的培训。非技术总结该奖项由材料研究部和化学部资助。它支持远离平衡稳态的生物分子系统和材料的理论研究和教育。大自然告诉我们，单个分子和分子复合物等小系统能够表现出丰富多样的动力学行为。 这种多样性的主要证据是在生物分子机器中发现的，这些机器执行维持生命所需的许多复杂任务：它们利用能量，将能量从一种形式转换为另一种形式，并忠实地复制和翻译遗传信息。 近年来，人们不仅在了解生物分子如何完成这些任务的细节方面，而且在合成模仿这种能力的人工分子机器方面，都有越来越多的兴趣和进展。 该奖项支持旨在揭示和阐明这些现象的基本物理定律的理论研究和教学。PI将更好地理解纳米系统能够执行涉及信息处理的任务的方法，如DNA的复制和修复。 对信息处理热力学的深入理解将为可编程人工分子机器的合成和改进提出策略。 PI还将分析微观系统如何响应温度，化学条件和激光的时间依赖性变化。 该研究旨在提高以可控方式操纵分子尺度事件的能力。该奖项资助的活动将为研究生和博士后做好准备，以应对物理学，化学和生物学交叉领域快速发展的主题的研究挑战。

TECHNICAL SUMMARYThis award is funded by the Division of Materials Research and the Chemistry Division. It supports theoretical research and education related to the nonequilibrium behavior of small systems, from biomolecular complexes to artificial molecular machines. The primary aim of the research is to advance basic understanding of the laws of thermodynamics and how they apply to nanoscale systems, where fluctuations are important and unavoidable. The PI's approach will include exact analysis of tractable models, theoretical and numerical modeling of systems studied experimentally, and the formulation of general principles. Two central questions to be addressed are:1) What fundamental constraints does statistical thermodynamics impose on the processing of information by molecular-level systems?2) What are the principles by which the directed motion of artificial molecular machines can be generated and controlled by the variation of macroscopic external parameters?The first question is motivated both by the reality that biomolecular systems do perform information-processing tasks, and artificial molecular machines are beginning to show this capability. The PI will develop models that capture essential features of information processing by autonomous molecular systems, while remaining accessible to exact analysis or numerical simulation. By exposing explicit, transparent mechanisms of operation, such models will offer simple paradigms for investigating the thermodynamics of information processing in situations where thermal fluctuations dominate.Research in the second question was originally motivated by experiments involving the manipulation of ring-like molecules, catenanes, by the variation of external stimuli. The aim is a systematic control theory for artificial molecular machines in the presence of substantial thermal noise. The PI will approach this problem within the general theoretical framework of stochastic pumps, in which a system makes random transitions among a network of discrete states, with time-dependent transition rates. Here the topology of the network plays an important role in the analysis.This award supports graduate student and postdoctoral level training in the methods of theoretical and computational statistical mechanics.NON-TECHNICAL SUMMARYThis award is funded by the Division of Materials Research and the Chemistry Division. It supports theoretical research and education on biomolecular systems and materials far from the steady state of equilibrium.Nature teaches us that small systems such as individual molecules and molecular complexes are capable of exhibiting a rich diversity of dynamical behavior. Prime evidence of this diversity is found in the biomolecular machines that perform the numerous and often sophisticated tasks required to maintain life: they harness energy, convert it from one form to another, and faithfully copy and translate genetic information. In recent years there has been growing interest and progress not only in understanding the details of how biological molecules accomplish these tasks, but also in synthesizing artificial molecular machines that mimic such capabilities. This award supports theoretical research and teaching that aims to uncover and clarify the basic physical laws that govern these phenomena.The PI will develop a better understanding of the means by which nanoscale systems are able to perform tasks that involve the processing of information, as occurs in the replication and repair of DNA. A deeper understanding of the thermodynamics of information processing will suggest strategies for the synthesis and improvement of programmable artificial molecular machines. The PI will also analyze how microscopic systems respond to time-dependent variations in temperature, chemical conditions and laser light. This research aims to advance the ability to manipulate events on the scale of molecules in a controlled manner.The activities funded by this award will prepare graduate students and postdocs for the challenges of research in rapidly evolving topics at the intersection of physics, chemistry and biology.