An optical topological transition is defined as the change in the photonic isofrequency surface around epsilon-near-zero (ENZ) frequencies which can considerably change the spontaneous emission of a quantum emitter placed near a metamaterial slab. Here, we show that due to the strong Kerr nonlinearity at ENZ frequencies, a high power pulse can induce a sudden transition in the topology of the iso-frequency dispersion curve, leading to a significant change in the transmission of propagating as well as evanescent waves through the metamaterial slab. This evanescent wave switch effect allows for the control of spontaneous emission through modulation of the Purcell effect. We develop a theory of the enhanced nonlinear response of ENZ media to s and p polarized inputs and show that this nonlinear effect is stronger for p polarization and is almost independent of the incident angle. We perform finite-difference time-domain (FDTD) simulations to demonstrate the transient response of the metamaterial slab to an ultrafast pulse and fast switching of the Purcell effect at the sub-picosecond scale. The Purcell factor changes at ENZ by almost a factor of three which is an order of magnitude stronger than that away from ENZ. We also show that due to the inhomogeneous spatial field distribution inside the multilayer metal-dielectric super-lattice, a unique spatial topological transition metamaterial can be achieved by the control pulse induced nonlinearity. Our work can lead to ultra-fast control of quantum phenomena in ENZ metamaterials.

中文翻译：

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使用非线性 epsilon-near-zero 介质切换 Purcell 效应

光学拓扑跃迁被定义为围绕 epsilon-near-zero (ENZ) 频率的光子等频表面的变化，这可以显着改变放置在超材料板附近的量子发射器的自发发射。在这里，我们表明，由于 ENZ 频率处的强克尔非线性，高功率脉冲会引起等频色散曲线拓扑结构的突然转变，导致传播和倏逝波的传输发生显着变化通过超材料板。这种渐逝波开关效应允许通过调制珀塞尔效应来控制自发发射。我们开发了一种 ENZ 介质对 s 和 p 偏振输入的增强非线性响应的理论，并表明这种非线性效应对于 p 偏振更强，并且几乎与入射角无关。我们执行有限差分时域 (FDTD) 模拟，以证明超材料板对超快脉冲的瞬态响应和亚皮秒级珀塞尔效应的快速切换。珀塞尔因子在 ENZ 的变化几乎是三倍，这比远离 ENZ 的要强一个数量级。我们还表明，由于多层金属电介质超晶格内部的空间场分布不均匀，因此可以通过控制脉冲引起的非线性来实现独特的空间拓扑跃迁超材料。