论文标题
二维材料在理论上极限附近具有巨大的光学非线性
Two-dimensional Materials with Giant Optical Nonlinearities Near the Theoretical Upper Limit
论文作者
论文摘要
非线性光学（NLO）现象，例如谐波产生，KERR和POCKELS效应，对于激光器，频率转换器，调节器，开关等方面具有非常重要的技术意义。最近，由于其强大而独特的NLO特性，二维（2D）材料引起了二维（2D）的关注。在这里，我们描述了一个有效的第一原理工作流程，用于计算二次光学响应，并将其应用于来自计算2D材料数据库（C2DB）的375个非中心对称半导体单层。对bandgap $ e_g $排序非共振的非线性揭示了与$ e_g^{ - 4} $成比例的上限，这是由两个不同的通用模型整齐地解释的。我们确定了多个有前途的候选人，其巨型非线性和带镜的范围从0.4到5 eV，其中一些接近理论上极限，并且非常跑步已知的材料。我们为所有375个单层的NLO Spectra的全面图书馆可通过C2DB网站免费获得。我们希望这项工作为基于2D材料的高效和紧凑的光电设备铺平道路。
Nonlinear optical (NLO) phenomena such as harmonic generation, Kerr, and Pockels effects are of great technological importance for lasers, frequency converters, modulators, switches, etc. Recently, two-dimensional (2D) materials have drawn significant attention due to their strong and unique NLO properties. Here, we describe an efficient first-principles workflow for calculating the quadratic optical response and apply it to 375 non-centrosymmetric semiconductor monolayers from the Computational 2D Materials Database (C2DB). Sorting the non-resonant nonlinearities with respect to bandgap $E_g$ reveals an upper limit proportional to $E_g^{-4}$, which is neatly explained by two distinct generic models. We identify multiple promising candidates with giant nonlinearities and bandgaps ranging from 0.4 to 5 eV, some of which approach the theoretical upper limit and greatly outperform known materials. Our comprehensive library of ab initio NLO spectra for all 375 monolayers is freely available via the C2DB website. We expect this work to pave the way for highly efficient and compact opto-electronic devices based on 2D materials.
