论文标题
使用陡峭的熵上升量子热力学预测二维PTSE $ _2 $中的缺陷稳定性和退火动力学
Predicting Defect Stability and Annealing Kinetics in Two-Dimensional PtSe$_2$ Using Steepest Entropy Ascent Quantum Thermodynamics
论文作者
论文摘要
最陡峭的量子量子热力学(SEAQT)框架用于计算2D PTSE $ _2 $中点缺陷集合的稳定性,并预测在热退火过程中缺陷重新排列的动力学。该框架提供了一个非平衡,基于整体的框架,并在力学(量子和经典)和热力学之间具有自一致的联系。它采用了源自陡峭的熵上升原理(最大熵产生)的原理的运动方程,以预测一组职业概率的时间演变,这些概率定义了正在进行非平衡过程的系统的状态。该系统由特征值的退化能量景观描述,并且从职业概率和特征级归化性中发现了熵。扫描隧道显微镜用于确定在2D PTSE $ _2 $膜中实验观察到的点缺陷的结构和分布。观察到的缺陷的目录包括六个独特的点缺陷(PT和SE Sublattices上的空缺和抗位点缺陷)和二十个在近距离接近的多点缺陷的组合。用密度功能理论(DFT)估算了缺陷能,而对于2D膜的归化性或密度,具有所有可能的组合或分类缺陷的排列的2D膜,使用非马克维亚蒙特卡洛方法(即replica-exchange-exchange-exchange-wangang-wang-andau algorithm algorithm)构建。确定了2D PTSE $ _2 $胶片厚度厚的2D PTSE $ _2 $ 30 \ $ 30 \ times 30 $单位细胞(总计5400个原子)的能源景观和相关的脱落。将SEAQT运动方程式应用于能量格局,以确定在退火过程中六种缺陷类型的任意密度和排列如何演变。
The steepest-entropy-ascent quantum thermodynamic (SEAQT) framework was used to calculate the stability of a collection of point defects in 2D PtSe$_2$ and predict the kinetics with which defects rearrange during thermal annealing. The framework provides a non-equilibrium, ensemble-based framework with a self-consistent link between mechanics (both quantum and classical) and thermodynamics. It employs an equation of motion derived from the principle of steepest entropy ascent (maximum entropy production) to predict the time evolution of a set of occupation probabilities that define the states of a system undergoing a non-equilibrium process. The system is described by a degenerate energy landscape of eigenvalues, and the entropy is found from the occupation probabilities and the eigenlevel degeneracies. Scanning tunneling microscopy was used to identify the structure and distribution of point defects observed experimentally in a 2D PtSe$_2$ film. A catalog of observed defects included six unique point defects (vacancies and anti-site defects on Pt and Se sublattices) and twenty combinations of multiple point defects in close proximity. The defect energies were estimated with density functional theory (DFT), while the degeneracies, or density of states, for the 2D film with all possible combinations or arrangements of cataloged defects was constructed using a non-Markovian Monte-Carlo approach (i.e., the Replica-Exchange-Wang-Landau algorithm) with a q-state Potts model. The energy landscape and associated degeneracies were determined for a 2D PtSe$_2$ film two molecules thick and $30 \times 30$ unit cells in area (total of 5400 atoms). The SEAQT equation of motion was applied to the energy landscape to determine how an arbitrary density and arrangement of the six defect types evolve during annealing.