论文标题
用列物液晶体涂有金属纳米颗粒的光散射
Light scattering by a metallic nanoparticle coated with a nematic liquid crystal
论文作者
论文摘要
我们研究了涂有列液晶的金纳米颗粒的光学特性，该液体晶体的主场根据纳米颗粒表面的锚固条件在纳米颗粒周围分布。通过最小化相应的Frank自由能功能，而光学响应通过离散偶极近似计算，列液晶的分布是通过最小化的。我们特别发现，列液晶涂层的各向异性不会影响纳米颗粒的（各向同性）光学响应。但是，对于在纳米颗粒表面上的列液晶分子的强锚定，由环形奇异性（披露或土星环）表现出的涂层的不均匀性，会在整个可见光谱中增强eRctionction的eRctionction。
We study the optical properties of gold nanoparticles coated with a nematic liquid crystal whose director field is distributed around the nanoparticle according to the anchoring conditions at the surface of the nanoparticle. The distribution of the nematic liquid crystal is obtained by minimization of the corresponding Frank free-energy functional whilst the optical response is calculated by the discrete-dipole approximation. We find, in particular, that the anisotropy of the nematic liquid-crystal coating does not affect much the (isotropic) optical response of the nanoparticle. However, for strong anchoring of the nematic liquid-crystal molecules on the surface of nanoparticle, the inhomogeneity of the coating which is manifested by a ring-type singularity (disclination or Saturn ring), produces an enhancement of the extinction cross spectrum over the entire visible spectrum.
