We theoretically propose a compound metasurface structure consisting of a patterned black phosphorus (BP) sheet sandwiched by dielectrics, which can achieve a tunable plasmon-induced transparency (PIT) effect in the mid-infrared region. The PIT effect can be actively adjusted by changing the geometric parameters and the carrier concentration of BP. The mechanism of PIT originates from the near-field coupling between the bright mode and the dark mode. The numerical simulation results are highly consistent with the theoretical calculations of the coupled Lorentz oscillator model. In addition, our proposed structure system exhibits a strong dispersion accompanied with a group index of ∼15, which provides a new strategy for slow light devices.

中文翻译：

---

亮-暗模式耦合基于单层黑磷的可调谐等离子体激元诱导的透明性

我们从理论上提出了一种复合的超表面结构，该结构由图案化的黑磷（BP）板夹在介电材料之间构成，该结构可以在中红外区域实现可调谐的等离激元诱导的透明性（PIT）效果。可以通过改变BP的几何参数和载流子浓度来主动调整PIT效果。PIT的机制起源于亮模式和暗模式之间的近场耦合。数值模拟结果与耦合洛伦兹振荡器模型的理论计算高度一致。此外，我们提出的结构系统表现出较强的色散性，群指数约为15，这为慢光设备提供了新的策略。