The design makes use of a patterned graphene sheet located on top of a substrate to realize the absorption of the incident electromagnetic field. The researchers demonstrate the possibility of using the resonant patterned graphene sheet to produce THz magnetism. This only naturally exists at lower frequencies above a few gigahertz. The design is equivalent to a thin slab of grounded metaferrite material and provides effective absorption even at higher frequencies.

Dynamic tunability

The dispersive effective permeability of this graphene-based metaferrite has a resonant frequency that can be tuned. This is through chemical doping or electrostatic gating that changes the graphene’s chemical potential. Electrostatic doping of the graphene sheet not only equips the design with dynamic tunability but can also be used as an on/off switch.

Metaferrite modelling

The study focuses on the optimal synthesis of realistic graphene metasurfaces - modelled through equivalent metaferrite materials - to design a tunable and modulatable THz absorber. In particular, the aim is to achieve the challenging broad- and/or multi-band operation via the use of multiple graphene metasurfaces stacked on top of each other.

The researchers presented their work in the journal Nanotechnology 26 164002.

Further reading

Small molecules make big differences to phosphorene (Feb 2015)
Multilayer molybdenum disulfide undergoes metallic transition under strain (Nov 2015)
Layered semiconductors: thickness changes conductivity (Sept 2014)