Javani Mohammad H, Stockman Mark I
Center for Nano-Optics (CeNO) and Department of Physics and Astronomy, Georgia State University, Atlanta, Georgia 30303, USA.
Phys Rev Lett. 2016 Sep 2;117(10):107404. doi: 10.1103/PhysRevLett.117.107404.
From the fundamental principle of causality we show that epsilon-near-zero (ENZ) materials with a very low (asymptotically zero) intrinsic dielectric loss do necessarily possess a very low (asymptotically zero) group velocity of electromagnetic wave propagation. This leads to the loss function being singular and causes high nonradiative damping of the optical resonators and emitters (plasmonic nanoparticles, quantum dots, chromophore molecules) embedded into them or placed at their surfaces. Rough ENZ surfaces do not exhibit hot spots of local fields suggesting that surface modes are overdamped. Reflectors and waveguides also show very large losses both for realistic and idealized ENZ materials.
从因果关系的基本原理出发，我们证明，具有极低（渐近为零）本征介电损耗的近零介电常数（ENZ）材料必然具有极低（渐近为零）的电磁波传播群速度。这导致损耗函数奇异，并使嵌入其中或置于其表面的光学谐振器和发射器（等离子体纳米颗粒、量子点、发色团分子）产生高非辐射阻尼。粗糙的ENZ表面未表现出局部场热点，这表明表面模式过阻尼。对于实际的和理想化的ENZ材料，反射器和波导也都表现出非常大的损耗。
