Polar biaxial crystals with extreme anisotropy hold promise for the spatial control and the manipulation of polaritons, as they can undergo topological transitions. However, taking advantage of these unique properties for nanophotonic devices requires to find mechanisms to modulate dynamically the material response. Here, we present a study on the propagation of surface phonon polaritons (SPhPs) in a photonic architecture based on a thin layer of α-MoO3 deposited on a semiconducting 4H-SiC substrate, whose carrier density can be tuned through photoinduction. By employing this system, we establish a comprehensive polaritonic platform where the propagation of the hybridized SPhPs can be manipulated dynamically due to their coupling with the electron plasma. Specifically, we demonstrate that increasing the doping of the 4H-SiC substrate allows for modulating the on/off switch behavior of SPhP propagation or its controlled canalization. Furthermore, this modulation leads to a notable increase in the Purcell factor, primarily attributed to the doping-induced flat dispersion curve creating ultra-slow light. These findings have significant implications for the development of nanophotonic and quantum technologies, as they enable the utilization of polaritonic materials exclusively.

中文翻译：

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通过 SiC 衬底动态掺杂调制 MoO3 中表面声子极化激元


具有极端各向异性的极性双轴晶体有望进行空间控制和操纵极化激元，因为它们可以经历拓扑转变。然而，利用纳米光子器件的这些独特特性需要找到动态调节材料响应的机制。在这里，我们提出了一项关于表面声子极化激元 （SPhP） 在光子结构中传播的研究，该光子结构基于沉积在半导体 4H-SiC 衬底上的 α-MoO3 薄层，其载流子密度可以通过光感应进行调整。通过使用该系统，我们建立了一个全面的极化极化平台，由于杂化 SPhPs 与电子等离子体的耦合，因此可以动态操纵杂化 SPhP 的传播。具体来说，我们证明增加 4H-SiC 衬底的掺杂可以调节 SPhP 传播或其受控通道化的开/关开关行为。此外，这种调制导致 Purcell 因子的显着增加，这主要归因于掺杂诱导的平坦色散曲线产生超慢光。这些发现对纳米光子和量子技术的发展具有重大意义，因为它们使极化子材料的利用成为可能。