论文标题
来自原子概率分布的二维固体中的声子分散
Phonon dispersion in two-dimensional solids from atomic probability distributions
论文作者
论文摘要
我们提出了一种谐波线性响应（HLR）方法，以计算有限温度下的平衡模拟中二维（2D）层的声子分散关系。这种HLR方法基于系统的线性响应，该方法源自对其在平衡路径积分模拟中的质心密度的分析。在经典限制中，这种方法与那些通过原子波动的协方差矩阵对角线化研究振动特性的方法密切相关。该方法的有效性在计算石墨烯单层，石墨烯双层和石墨烷的声子分散关系的计算中进行了测试。通过计算以下可观察到的温度依赖性：碳原子的动能，光学$ e_ {2g} $模式的振动频率和层的弹性模量，可以证明石墨烯中语音分散关系中的非谐作用。
We propose a harmonic linear response (HLR) method to calculate the phonon dispersion relations of two-dimensional (2D) layers from equilibrium simulations at finite temperature. This HLR approach is based on the linear response of the system, as derived from the analysis of its centroid density in equilibrium path integral simulations. In the classical limit, this approach is closely related to those methods that study vibrational properties by the diagonalization of the covariance matrix of atomic fluctuations. The validity of the method is tested in the calculation of the phonon dispersion relations of a graphene monolayer, a graphene bilayer, and graphane. Anharmonic effects in the phonon dispersion relations of graphene are demonstrated by the calculation of the temperature dependence of the following observables: the kinetic energy of the carbon atoms, the vibrational frequency of the optical $E_{2g}$ mode, and the elastic moduli of the layer.
