Computer Simulations of Phase Transitions

0094422 Landau计算机模拟是一个强大的工具，用于获得统计物理学中广泛问题的基本信息，并补充传统的理论和实验方法。 该补助金支持一个关于统计系统计算机模拟的广泛计划。 作为这项工作的一部分，大规模的模拟方法将开发和完善的相变系统的研究，这是很难处理的分析。 将使用的技术包括各种蒙特卡罗和自旋动力学模拟，这些模拟已经非常完善。 模型将被检查相关的磁性材料（包括系统表现出巨大的磁阻），二元半导体合金，生长薄膜，和无序介质。 一些系统包括可以在空间中连续移动并受到弹性相互作用的粒子，而其他系统将被限制在具有离散近邻相互作用的刚性晶格（包括具有连续自由度的经典自旋）。 在许多系统中，有限的几何形状和/或壁的存在是导致不同于在本体中发现的行为的原因。 静态和动态的临界现象系统平衡将仔细检查，简单的非平衡模型有关的薄膜生长和超离子扩散将使用Monte Carlo和动力学Monte Carlo方法进行研究。 如有可能，将结果与分析理论和/或实验进行比较。%计算机模拟是一种强有力的工具，用于获得有关统计物理中广泛问题的基本信息，并补充传统的理论和实验方法。 这项拨款支持一个广泛的计算机模拟项目。 计算技术将得到发展和完善，这些技术将应用于各种物理系统。***

0094422LandauComputer simulations are a powerful tool for obtaining fundamental information about wide ranging problems in statistical physics and to complement traditional theoretical and experimental methods. This grant supports a broad program on computer simulations of statistical systems. As part of this effort, large scale simulation methods will be developed and refined for the study of phase transitions in systems which are difficult to treat analytically. Techniques to be used include diverse Monte Carlo and Spin Dynamics simulations which have been exceedingly well refined. Models to be examined will be relevant to magnetic materials (including systems which exhibit colossal magnetoresistance), binary semiconductor alloys, growing films, and disordered media. Several of the systems include particles which may move continuously in space and which are subject to elastic interactions, whereas others will be confined to rigid lattices (including classical spins with continuous degrees of freedom) with discrete near-neighbor interactions. In many of the systems finite geometries and/or the presence of walls are responsible for behavior which is different than that which is found in the bulk. Both static and dynamic critical phenomena for systems in equilibrium will be carefully examined, and simple non-equilibrium models related to film growth and superionic diffusion will be studied using Monte Carlo and Kinetic Monte Carlo methods. Where possible, results will be compared with analytical theory and/or experiment.%%%Computer simulations are a powerful tool for obtaining fundamental information about wide ranging problems in statistical physics and to complement traditional theoretical and experimental methods. This grant supports a broad program on computer simulations. Computational techniques will be developed and refined, and these techniques will be applied to a variety of physics systems. ***