论文标题
准确的远距离介电筛选和准2D晶体中的原子间力常数
Exact long-range dielectric screening and interatomic force constants in quasi-2D crystals
论文作者
论文摘要
我们通过对库仑内核的非分析性进行严格研究来开发二维晶体中远程静电相互作用的基本理论。我们发现，介电函数最好由$ 2 \ times 2 $矩阵表示，其宏观电位不均匀，这是平面外坐标的两个组件双曲线功能，$ z $。我们通过在绝热政权中得出远距离的原子质力来证明我们的论点，在那里我们确定了涉及动态电荷的平面成分的以前被忽视的偶极耦合。所得公式精确地达到了任意多极顺序，我们在实践中通过明确包含动态四极杆进行了说明。通过对单层BN，SNS $ _2 $和BATIO $ _3 $ MEMBRANES进行数值测试，我们表明我们的方法可以在描述远程静电相互作用的描述方面进行了巨大改进，并具有可比的好处，可与插值声子结构的质量相当。
We develop a fundamental theory of the long-range electrostatic interactions in two-dimensional crystals by performing a rigorous study of the nonanalyticities of the Coulomb kernel. We find that the dielectric functions are best represented by $2\times 2$ matrices, with nonuniform macroscopic potentials that are two-component hyperbolic functions of the out-of-plane coordinate, $z$. We demonstrate our arguments by deriving the long-range interatomic forces in the adiabatic regime, where we identify a formerly overlooked dipolar coupling involving the out-of-plane components of the dynamical charges. The resulting formula is exact up to an arbitrary multipolar order, which we illustrate in practice via the explicit inclusion of dynamical quadrupoles. By performing numerical tests on monolayer BN, SnS$_2$ and BaTiO$_3$ membranes, we show that our method allows for a drastic improvement in the description of the long-range electrostatic interactions, with comparable benefits to the quality of the interpolated phonon band structure.
