In this paper we propose a graphene-based metasurface structure that can exhibit tunable electromagnetically-induced-transparency-like (EIT) spectral response at mid-infrared frequencies. The metasurface structure is composed of two subwavelength mono-layer graphene nano-disks coupled with a mono-layer graphene nano-strip. We show that the coupling of the nano-disks' dipole resonance with the quadrupole resonance of the nano-strip can create two split resonances with a transparency window in between at any desired center frequency within a wide frequency range. We show that such an EIT-like response can also be dynamically shifted in frequency by adjusting the Fermi-level of the graphene through external voltage control, which provides convenient post-fabrication tunability. In addition, the performance of such a metastructure for sensing the refractive index of the surrounding medium is analyzed. The simulation results show that its sensitivity can reach 3016.7 nm/(RIU) with a FOM exceeding 12.0. Lastly, we present an analysis of the slow light characteristics of the proposed device, where the group index can reach as large as 200. Our design provides a new miniaturized sensing platform that can facilitate the development of biochemical molecules testing, etc.

中文翻译：

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基于石墨烯超材料的可调电磁感应透明性。

在本文中，我们提出了一种基于石墨烯的超表面结构，该结构在中红外频率下可显示出可调谐的电磁感应类透明（EIT）光谱响应。超表面结构由两个亚波长单层石墨烯纳米盘与单层石墨烯纳米带耦合而成。我们表明，纳米圆盘的偶极共振与纳米带的四极共振的耦合可以在宽频率范围内任何所需的中心频率之间创建两个具有透明窗口的分裂共振。我们表明，通过外部电压控制通过调节石墨烯的费米能级，还可以动态改变此类EIT响应的频率，从而提供了方便的制造后可调性。此外，分析了这种用于检测周围介质折射率的元结构的性能。仿真结果表明，当FOM超过12.0时，其灵敏度可达3016.7 nm /（RIU）。最后，我们对拟议器件的慢光特性进行了分析，该器件的组指数可高达200。我们的设计提供了一个新的小型感测平台，可促进生化分子测试等的发展。