Department of Physics and Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, United States.
Nano Lett. 2013 Mar 13;13(3):1111-7. doi: 10.1021/nl304476b. Epub 2013 Feb 19.
Graphene is widely known for its anomalously strong broadband optical absorptivity of 2.3% that enables seeing its single-atom layer with the naked eye. However, in the mid-infrared part of the spectrum graphene represents a quintessential lossless zero-volume plasmonic material. We experimentally demonstrate that, when integrated with Fano-resonant plasmonic metasurfaces, single-layer graphene (SLG) can be used to tune their mid-infrared optical response. SLG's plasmonic response is shown to induce large blue shifts of the metasurface's resonance without reducing its spectral sharpness. This effect is explained by a generalized perturbation theory of SLG-metamaterial interaction that accounts for two unique properties of the SLG that set it apart from all other plasmonic materials: its anisotropic response and zero volume. These results pave the way to using gated SLG as a platform for dynamical spectral tuning of infrared metamaterials and metasurfaces.
石墨烯因其异常强的宽带光吸收率（高达 2.3%）而广为人知，这种吸收率可使单层石墨烯肉眼可见。然而，在光谱的中红外部分，石墨烯代表了一种典型的无损零体积等离子体材料。我们通过实验证明，当与具有 Fano 共振的等离子体超表面集成时，单层石墨烯 (SLG) 可用于调节它们的中红外光响应。实验表明，SLG 的等离子体响应会引起超表面共振的大幅蓝移，而不会降低其光谱锐度。这种效应可以通过 SLG-超材料相互作用的广义微扰理论来解释，该理论考虑了 SLG 的两个独特特性，使其有别于所有其他等离子体材料：各向异性响应和零体积。这些结果为使用门控 SLG 作为动态调节红外超材料和超表面光谱的平台铺平了道路。
