Sloan Jamison, Rivera Nicholas, Joannopoulos John D, Soljačić Marin
Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Phys Rev Lett. 2021 Jul 30;127(5):053603. doi: 10.1103/PhysRevLett.127.053603.
Time-varying optical media, whose dielectric properties are actively modulated in time, introduce a host of novel effects in the classical propagation of light, and are of intense current interest. In the quantum domain, time-dependent media can be used to convert vacuum fluctuations (virtual photons) into pairs of real photons. We refer to these processes broadly as "dynamical vacuum effects" (DVEs). Despite interest for their potential applications as sources of quantum light, DVEs are generally very weak, presenting many opportunities for enhancement through modern techniques in nanophotonics, such as using media which support excitations such as plasmon and phonon polaritons. Here, we present a theory of weakly modulated DVEs in arbitrary nanostructured, dispersive, and dissipative systems. A key element of our framework is the simultaneous incorporation of time-modulation and "dispersion" through time-translation-breaking linear response theory. As an example, we use our approach to propose a highly efficient scheme for generating entangled surface polaritons based on time-modulation of the optical phonon frequency of a polar insulator.
时变光学介质，其介电特性随时间动态调制，在光的经典传播中引入了许多新颖效应，目前备受关注。在量子领域，随时间变化的介质可用于将真空涨落（虚光子）转化为实光子对。我们将这些过程统称为“动态真空效应”（DVE）。尽管DVE因其作为量子光源的潜在应用而受到关注，但它们通常非常微弱，这为通过纳米光子学中的现代技术进行增强提供了许多机会，例如使用支持诸如等离激元和声子极化激元等激发的介质。在此，我们提出了一种关于任意纳米结构、色散和耗散系统中弱调制DVE的理论。我们框架的一个关键要素是通过打破时间平移的线性响应理论同时纳入时间调制和“色散”。作为一个例子，我们使用我们的方法提出了一种基于极性绝缘体光学声子频率的时间调制来产生纠缠表面极化激元的高效方案。
