论文标题
高索引拓扑绝缘子bismuth trinuride启用了深层谐振的呼吸器
Deep-subwavelength resonant metaphotonics enabled by high-index topological insulator bismuth telluride
论文作者
论文摘要
在纳米光子学，小模式量，高质量因子（Q）共振和没有金属的大型田间增强功能，从根本上讲，折射率是折射率的，并且对于许多涉及轻质相互作用的实现都是关键。拓扑绝缘子（TI）是一类绝缘材料，这些绝缘材料托有拓扑保护的表面状态，其中一些表现出非凡的高介电常数值。在这里，我们研究Ti Bismuth Telluride（BI2TE3）单晶的光学性质。我们发现，散装状态和表面状态都有助于极大的光学常数，而折射率的实际部分在n〜11处达到峰值。利用这些超高指数值，我们证明了BI2TE3跨空面力能够在深度亚波长结构中挤压光，其基本磁性偶极子（MD）共振限制在小于λ/10的单位细胞大小中。我们进一步表明，密集的超薄跨表面阵列可以同时提供由表面金属状态和大量高指数引起的大型磁场和电场增强。这些发现证明了硫族化物Ti材料作为一个平台，该平台利用超高指数介电响应与表面金属状态的独特组合用于超材料设计和纳米光子在感应，非线性产生和量子信息中的应用。
In nanophotonics, small mode volumes, high-quality factor (Q) resonances, and large field enhancements without metals, fundamentally scale with the refractive index and are key for many implementations involving light-matter interactions. Topological insulators (TI) are a class of insulating materials that host topologically protected surface states, some of which exhibit extraordinary high permittivity values. Here, we study the optical properties of TI bismuth telluride (Bi2Te3) single crystals. We find that both the bulk and surface states contribute to the extremely large optical constants, with the real part of the refractive index peaking at n~11. Utilizing these ultra-high index values, we demonstrate that Bi2Te3 metasurfaces are capable of squeezing light in deep subwavelength structures, with the fundamental magnetic dipole (MD) resonance confined in unit cell size smaller than λ/10. We further show that dense ultrathin metasurface arrays can simultaneously provide large magnetic and electric field enhancements arising from the surface metallic states and the high index of the bulk. These findings demonstrate the potential of chalcogenide TI materials as a platform leveraging the unique combination of ultra-high-index dielectric response with surface metallic states for metamaterial design and nanophotonic applications in sensing, non-linear generation, and quantum information.
