连接晶体和准晶体的转变途径。
Transition pathways connecting crystals and quasicrystals.
机构信息
Laboratory of Mathematics and Applied Mathematics, School of Mathematical Sciences, Peking University, Beijing 100871, China.
School of Mathematics and Computational Science, Xiangtan University, Hunan 411105, China.
出版信息
Proc Natl Acad Sci U S A. 2021 Dec 7;118(49). doi: 10.1073/pnas.2106230118.
Due to structural incommensurability, the emergence of a quasicrystal from a crystalline phase represents a challenge to computational physics. Here, the nucleation of quasicrystals is investigated by using an efficient computational method applied to a Landau free-energy functional. Specifically, transition pathways connecting different local minima of the Lifshitz-Petrich model are obtained by using the high-index saddle dynamics. Saddle points on these paths are identified as the critical nuclei of the 6-fold crystals and 12-fold quasicrystals. The results reveal that phase transitions between the crystalline and quasicrystalline phases could follow two possible pathways, corresponding to a one-stage phase transition and a two-stage phase transition involving a metastable lamellar quasicrystalline state, respectively.
由于结构上的不可通约性，准晶体从晶体相的出现对计算物理学提出了挑战。在这里，通过应用于朗道自由能泛函的有效计算方法来研究准晶体的成核。具体来说，通过使用高指数鞍点动力学获得了连接 Lifshitz-Petrich 模型不同局部最小值的转变途径。这些路径上的鞍点被确定为 6 重晶体和 12 重准晶体的临界核。结果表明，晶体相与准晶体相之间的相变可以遵循两种可能的途径，分别对应于一阶相变和涉及亚稳层状准晶态的两阶段相变。
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