论文标题
高折射率和极端双轴光学各向异性，用于在全磁纳米素中应用
High refractive index and extreme biaxial optical anisotropy of rhenium diselenide for applications in all-dielectric nanophotonics
论文作者
论文摘要
我们建立了简单的定量标准，用于搜索具有可见范围内折射率高值的新介电材料。可以证明，对于频带间隙下方的光频率，后者由无量纲参数$η$确定，该参数$η$计算为传导和价带宽度和价频段的宽度之比和带隙。该参数的少量值可以在几乎平坦的带中实现，从而导致折射率的急剧增加。我们用一个特定的二钙构剂的例子来说明这一规则，为此，我们对频带结构和光感敏感性进行了ab-Initio计算，并在1 eV附近的宽频率范围内预测了折射率> 5的值，以及含量较低的损失。我们的发现开放了新的观点，以寻找全核纳米光子学的新的高指数/低损失材料。
We establish simple quantitative criterium for the search of new dielectric materials with high values of the refractive index in the visible range. It is demonstrated, that for light frequencies below the band gap the latter is determined by the dimensionless parameter $η$ calculated as the ratio of the sum of the widths of conduction and valence bands and the band gap. Small values of this parameter, which can be achieved in materials with almost flat bands, lead to dramatic increase of the refractive index. We illustrate this rule with a particular example of rhenium dichalcogenides, for which we perform ab-initio calculations of the band structure and optical susceptibility and predict the values of the refractive index > 5 in a wide frequency range around 1 eV together with compratively low losses. Our findings open new perspectives in the search for the new high-index/low loss materials for all-dielectric nanophotonics.
