Plasmon-induced transparency in graphene with double asymmetric L strips

In this work, plasmon-induced transparency has been realized with graphene metamaterial consisting of double asymmetric L strips. Due to the weak hybridization between this two L strip resonator, a clear transparency window on the transmission spectrum of the originally opaque frequency range can be realized. With a Lorentz coupled oscillator model, our theoretical results of the transmission spectra agree well with the numerical calculations. Moreover, the transparency window can be dynamically modulated via regulating the Fermi energy and carrier mobility. The reflection and absorption spectrum has also been analyzed concretely, and its absorption rate approaches as high as 50%, which provides a solid application in terahertz absorbers. According to the effective medium theory, the sensitivity of the transparency window as a function of the surrounding medium embodies a linear relationship. As for its dispersion behavior, the group index of the structure can reach up to 1125. This work shadows a fascinating application in the area of highly integrated sensor devices, filters or absorbers. (paper)