フォトニック結晶におけるフェルミ弧状態を利用した超高感度ガス検出

We demonstrate a gas detector based on sensitive Tamm plasmon polaritons (TPPs) at the interface between a 1D photonic crystal (PC) and a monolayer graphene sheet. To obtain those states and control their properties for a chosen wavelength, we map Fermi arc states existing in a synthetic geometrical space into real-space interface TPP states, which enables us to design a structure allowing detection of an ultralow concentration of NO₂, i.e., below 1 ppb. We also present that a simple addition of a defect layer may deliver a mechanism for a quantitative measurement of gas concentration. We demonstrate that our device, despite its simple design and single-surface gas exposure, overcomes sensitivity limitations of a standalone graphene monolayer to a level unprecedented in similar graphene-based sensor setups.