Tunable double plasmon-induced transparency based on monolayer patterned graphene metamaterial

The present study proposes a monolayer graphene metamaterial fabricated with periodic patterns, composed of three graphene nanostrips and a graphene rectangle (GR). The transmission spectra of the proposed metamaterial are calculated by means of the Finite-Difference Time-Domain (FDTD) simulation and the coupled mode theory (CMT). And double plasmon-induced transparency (DPIT) in the terahertz (THz) spectrum is achieved. Its spectral properties with different geometrical parameters, Fermi energy levels, and carrier mobility values are explored. In addition, we examine how adjusting the Fermi energy and carrier mobility influences the slow light phenomenon. An elevation of the group index to 600 is achieved by optimizing carrier mobility to <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <m:mn>3.0</m:mn> <m:mspace width="0.28em"/> <m:msup> <m:mrow> <m:mtext>m</m:mtext> </m:mrow> <m:mrow> <m:mn>2</m:mn> </m:mrow> </m:msup> <m:mo>/</m:mo> <m:mfenced close=")" open="("> <m:mrow> <m:mtext>V</m:mtext> <m:mspace width="0.28em"/> <m:mtext>s</m:mtext> </m:mrow> </m:mfenced> </m:math> 3.0 m²/(V s) . As a result, this graphene-based metamaterial shows valuable guidance for plasmonic slow light components in optical buffering.