Efficient Computation of Epitaxial Growth

外延生长的高效计算

• 批准号: 0509124
• 负责人: Peter Smereka
• 金额: $ 23.61万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0509124&HistoricalAwards=false
• 关键词: Efficient; Computation; Epitaxial; Growth

Epitaxial growth is a physical process where atoms are slowly deposited onto a substrate so that a crystal is grown, loosely speaking, one atomistic layer at a time. This is a fundamental scientific problem in which both nanoscale and macroscale effects are important. The resulting film morphology is determined by a complex interaction between thermodynamic and kinetic effects. In addition, epitaxial growth techniques have been used to create novel materials which contain quantum dots (nanometer sized collections of atoms embedded in a matrix of different species of atoms). The resulting material has unique electronic properties. For example, solid-state lasers have been made out of such materials. In addition, there is hope that such materials may be useful in quantum computing applications. Modeling the growth of such a material is still in its infancy.The purpose of this proposal is to develop efficient algorithms for the simulation of epitaxial growth using a computer. The proposal will focus on atomistic models rather than continuous ones since they naturally include nanoscale physical effects such as nucleation and fluctuations. In particular, kinetic Monte Carlo models will be used, in which simple rules for atom motion are evolved in stochastic fashion. The proposal aims at devising efficient computational methods to simulate such models. Our computational strategy is based on coarse-graining both in time and space, taking special care to preserve physical fidelity. Preliminary results indicate that our algorithms are 5 to 10 times faster than the current state-of-the-art. It is felt that the numerical methods proposed here will allow model development to proceed at a much faster pace, thereby facilitating the design of new materials. The proposer plans to work closely with two experimental research groups in the Material Science and Engineering Departments at the University of Michigan.

外延生长是一种物理过程，其中原子缓慢沉积到基板上，从而使晶体生长，宽泛地说，一次生长一个原子层。 这是一个基本的科学问题，纳米尺度和宏观尺度的效应都很重要。 所得薄膜的形态由热力学和动力学效应之间复杂的相互作用决定。此外，外延生长技术已被用来制造含有量子点（嵌入不同种类原子矩阵中的纳米尺寸原子集合）的新型材料。 所得材料具有独特的电子特性。 例如，固态激光器就是由此类材料制成的。此外，此类材料有望在量子计算应用中发挥作用。 对这种材料的生长进行建模仍处于起步阶段。该提案的目的是开发使用计算机模拟外延生长的有效算法。该提案将重点关注原子模型而不是连续模型，因为它们自然包括纳米级物理效应，例如成核和波动。 特别是，将使用动力学蒙特卡罗模型，其中原子运动的简单规则以随机方式演化。该提案旨在设计有效的计算方法来模拟此类模型。我们的计算策略基于时间和空间上的粗粒度，特别注意保持物理保真度。 初步结果表明，我们的算法比当前最先进的算法快 5 到 10 倍。 人们认为，这里提出的数值方法将使模型开发以更快的速度进行，从而促进新材料的设计。提议者计划与密歇根大学材料科学和工程系的两个实验研究小组密切合作。