Computer Simulations of Phase Transitions

该奖项支持使用最先进的计算机模拟的理论研究和教育。 这项研究补充了传统的理论和实验方法，研究了统计物理中涉及相变的挑战性问题。该研究计划的范围是多样化的，广泛开发方法来研究不能分析处理的系统中的相变。所使用的方法包括蒙特卡罗和自旋动力学模拟，这些方法采用了研究小组正在改进的复杂软件包。 这是正在进行的探索和开发以及改进新的大规模模拟方法的重要努力的一部分。一组不同的物理系统进行检查，特别注意那些与磁性材料，生长膜，聚合物和蛋白质。静态和动态的临界现象，系统在平衡的检查，这包括简单的非平衡模型有关的薄膜生长和超离子扩散（驱动扩散系统）。蒙特卡罗模拟被用来探索模型与耦合的磁和弹性自由度，晶格系统的几何挫折（物理系统与内在的局部挫折之间的磁自旋烧绿石晶格）或竞争的相互作用，和系统与有限的几何形状和相关的边界。由此产生的行为，这是根本不同的，这是在散装发现，是一个主要的动机的研究。自旋动力学模拟也用于探索平衡系统的动力学现象。非平衡态行为的研究，在模型中有关的薄膜生长和超离子扩散的研究使用Monte Carlo和动力学Monte Carlo方法。并与理论和实验结果进行了比较。相变行为和可能的新普适性类的发现和解释与预期的方法论发展相结合，形成了具有实质性知识实质的连贯活动，所做的努力具有更广泛的科学和教育影响。在其他领域也有许多类似的现象，对这些系统的理解也将得到加强。例如，蛋白质折叠的问题有很多共同点，例如，一个粗糙的？能源景观？带着挫败感的磁性模型。 许多算法的实现和进步适用于不同领域的广泛模拟。在许多研究的子领域（包括化学、生物化学和统计学）中，Wang-Landau抽样的改进是广泛适用的。该研究为研究生提供了广泛的计算机模拟方法的培训，使他们能够在多个相关领域从事科学事业。模拟物理中心在进行这项工作的地方有一个良好的记录，教育研究生从其他机构以及那些从格鲁吉亚大学。该中心主办的年度研讨会继续提供一个交流思想和信息的论坛。非技术性总结：该奖项支持使用最先进的计算机模拟的研究和教育。 这项研究补充了传统的理论和实验方法，研究了统计物理中涉及相变的挑战性问题。该研究计划的范围是多样的，广泛的发展方法来研究不能分析处理的系统中的相变。该研究小组正在改进采用复杂软件包的方法。 这是正在进行的探索和开发以及改进新的大规模计算机模拟方法的重要努力的一部分。一组不同的物理系统进行检查，特别注意那些与磁性材料，生长膜，聚合物和蛋白质。研究平衡系统的静态和动态现象，其中包括与薄膜生长和驱动扩散系统相关的简单非平衡模型。 计算机模拟用于探索具有有限几何形状和相关边界的系统模型。由此产生的行为，这是根本不同的，这是在散装发现，是一个主要的动机的研究。 并与理论和实验结果进行了比较。相变行为和可能的新相变的发现和解释与预期的方法学发展相结合，形成了具有实质性知识实质的连贯活动。所做的努力具有更广泛的科学和教育影响。在其他领域也有许多类似的现象，对这些系统的理解也将得到加强。例如，蛋白质折叠问题与所研究的磁性模型有许多共同之处。 计算机模拟方法的许多进展适用于不同领域的广泛模拟。在许多调查的子领域（包括化学，生物化学和统计学），这些改进当然是适用的。该研究为研究生提供了广泛的计算机模拟方法的培训，使他们能够在多个相关领域从事科学事业。模拟物理中心在进行这项工作的地方有一个良好的记录，教育研究生从其他机构以及那些从格鲁吉亚大学。中心主办的年度讲习班继续为交流想法和信息提供论坛。

TECHNICAL SUMMARY:This award supports theoretical research and education in the use of state-of-the-art computer simulations. The research complements traditional theoretical and experimental approaches in the study of challenging problems in statistical physics that involve phase transitions. The program of research is diverse in scope, broadly developing methods to study phase transitions in systems that cannot be treated analytically. The methods used include Monte Carlo and Spin Dynamics simulations and these employ sophisticated software packages are being enhanced by the research group. This is part of a significant effort in the ongoing exploration and development and refinement of new large-scale simulation methods. A diverse set of physical systems are examined with particularly attention to those with relevance to magnetic materials, growing films, polymers, and proteins. Both static and dynamic critical phenomena for systems in equilibrium are examined, and this includes simple non-equilibrium models related to film growth and superionic diffusion (driven diffusive systems). Monte Carlo simulations are used to explore models with coupled magnetic and elastic degrees of freedom, lattice systems with geometric frustration (a physical system with intrinsic local frustration between magnetic spins on a pyrochlore lattice) or competing interactions, and systems with finite geometries and associated boundaries. The resulting behavior, which is fundamentally different than that which is found in the bulk, is a primary motivator of the research. Spin dynamics simulations are also used to explore dynamic phenomena for systems in equilibrium. Nonequilibrium behavior is examined in models related to film growth and superionic diffusion is studied using Monte Carlo and Kinetic Monte Carlo methods. The results are compared with those from theory and experiment. The combination of the discovery and explanation of the phase transition behavior and possible new universality classes together with the anticipated methodological developments forms a coherent activity with substantive intellectual substance.The effort undertaken has broader impacts with both scientific and educational consequences. There are many analogous phenomena in other fields, and the understanding of those systems will also be enhanced. For example, the problem of protein folding has much in common, e.g. a rough ?energy landscape?, with magnetic models with frustration. Many of the algorithmic implementations and advances have applicability to a wide range of simulations in different areas. In many sub-areas of investigation (including chemistry, biochemistry, and statistics) the improvements in Wang-Landau sampling are broadly applicable. The research provides training of graduate students in a broad range of computer simulation methods and enables them to pursue scientific careers in multiple related fields. The Center for Simulational Physics where this work is carried out has an excellent record of educating graduate students from other institutions as well as those from The University of Georgia. The annual Workshop hosted by the Center continues to provide a forum for exchange of ideas and information.NONTECHNICAL SUMMARY:This award supports research and education in the use of state-of-the-art computer simulations. The research complements traditional theoretical and experimental approaches in the study of challenging problems in statistical physics that involve phase transitions. The program of research is diverse in scope, broadly developing methods to study phase transitions in systems that cannot be treated analytically. The methods employ sophisticated software packages are being enhanced by the research group. This is part of a significant effort in the ongoing exploration and development and refinement of new large-scale computer simulation methods. A diverse set of physical systems are examined with particularly attention to those with relevance to magnetic materials, growing films, polymers, and proteins. Both static and dynamic phenomena for systems in equilibrium are examined, and this includes simple non-equilibrium models related to film growth and driven diffusive systems. Computer simulations are used to explore models of systems with finite geometries and associated boundaries. The resulting behavior, which is fundamentally different than that which is found in the bulk, is a primary motivator of the research. The results are compared with those from theory and experiment. The combination of the discovery and explanation of the phase transition behavior and possible new phase transitions together with the anticipated methodological developments forms a coherent activity with substantive intellectual substance.The effort undertaken has broader impacts with both scientific and educational consequences. There are many analogous phenomena in other fields, and the understanding of those systems will also be enhanced. For example, the problem of protein folding has much in common with magnetic models studied. Many of the advances in computer simulation methods have applicability to a wide range of simulations in different areas. In many sub-areas of investigation (including chemistry, biochemistry, and statistics) the improvements are certainly applicable. The research provides training of graduate students in a broad range of computer simulation methods and enables them to pursue scientific careers in multiple related fields. The Center for Simulational Physics where this work is carried out has an excellent record of educating graduate students from other institutions as well as those from The University of Georgia. The annual Workshop hosted by the Center continues to provide a forum for exchange of ideas and information.