Electrically Switchable Metadevices via Graphene

TL;DR

This paper introduces electrically reconfigurable metadevices using graphene integrated with passive metamaterials, enabling dynamic control of electromagnetic wave properties and paving the way for advanced adaptive and cloaking applications.

Contribution

It demonstrates a novel hybrid system combining graphene with metamaterials to achieve active control over microwave electromagnetic responses.

Findings

Control of amplitude > 50 dB and phase > 90° of waves

Reconfigurable resonance frequency of split ring resonators

Spatially varying digital metasurfaces with bias voltages

Abstract

Metamaterials bring sub-wavelength resonating structures together to overcome the limitations of conventional materials. The realization of active metadevices has been an outstanding challenge that requires electrically reconfigurable components operating over a broad spectrum with a wide dynamic range. The existing capability of metamaterials, however, is not sufficient to realize this goal. Here, by integrating passive metamaterials with active graphene devices, we demonstrate a new class of electrically controlled active metadevices working in microwave frequencies. The fabricated active metadevices enable efficient control of both amplitude (> 50 dB) and phase (> 90{\deg}) of electromagnetic waves. In this hybrid system, graphene operates as a tunable Drude metal that controls the radiation of the passive metamaterials. Furthermore, by integrating individually addressable arrays of metadevices, we demonstrate a new class of spatially varying digital metasurfaces where the local dielectric constant can be reconfigured with applied bias voltages. Additionally, we reconfigure resonance frequency of split ring resonators without changing its amplitude by damping one of the two coupled metasurfaces via graphene. Our approach is general enough to implement various metamaterial systems that could yield new applications ranging from electrically switchable cloaking devices to adaptive camouflage systems.