在双Lamder模型中实现可调控光子带隙

研究驻波场相干驱动下四能级双Lamder模型的电磁感应光子带隙。当耦合场是远共振或共振时，来自于两邻近能级间的自发辐射相干效应(SGC)有助于实现一个或两个光子带隙。当自发辐射相干效应不存在时，探测场被原子系统强烈吸收，因此导致光子带隙严重形变甚至无法形成。数值结果表明，光子带隙结构是由SGC效应导致探测场和耦合场之间的相干增强Kerr非线性调制而产生，并改变驻波场的耦合方式，使系统实现单光子带隙转变为双光子带隙的动态调控。

Tunable photonic bandgap in Double Lamder configuration

We investigate a four level double lamder system with spontaneously generated coherence (SGC) for achieving photonic band gaps (PBG) by a standing-wave field. When the coupling field is far away from resonance or resonant, we can obtain one-phonon bandgap or two-phonon bandgap due to spontaneous emission coherent from two decay pathways. When the SGC is absent, the probe field is absorbed by the medium, so the PBG cannot be generated. The numerical calculations show that the induced PBG result from the Kerr nonlinear modulation between the probe and coupling field, and by controlling the detunings of coupling field, one PBG can be dynamically tuned into two PBGs in this system.