论文标题
二维材料中的直接和匡威挠性电性
Direct and converse flexoelectricity in two-dimensional materials
论文作者
论文摘要
在电子结构方法的最新发展的基础上，我们定义和计算第一原理中二维（2D）材料的挠性响应。特别是，我们表明，对弯曲变形的开路电压响应是晶体的基本线性响应特性，可以在平坦构型的原始单位单元格中计算。对石墨烯，硅，磷烯，bn和过渡金属二烷核单层的应用，分别存在两个不同的贡献，分别具有纯电子和晶格介导的性质。在前者中，我们确定了一个关键$公制$术语，该项由不受干扰的电荷密度的四极矩组成。我们提出了一个简单的连续模型，以将我们的发现与相反挠性效应的可用实验测量联系起来。
Building on recent developments in electronic-structure methods, we define and calculate the flexoelectric response of two-dimensional (2D) materials fully from first principles. In particular, we show that the open-circuit voltage response to a flexural deformation is a fundamental linear-response property of the crystal that can be calculated within the primitive unit cell of the flat configuration. Applications to graphene, silicene, phosphorene, BN and transition-metal dichalcogenide monolayers reveal that two distinct contributions exist, respectively of purely electronic and lattice-mediated nature. Within the former, we identify a key $metric$ term, consisting in the quadrupolar moment of the unperturbed charge density. We propose a simple continuum model to connect our findings with the available experimental measurements of the converse flexoelectric effect.
