# Broadband Three-Mode Tunable Metamaterials Based on Graphene and Vanadium Oxide

## TL;DR

This paper introduces a tunable terahertz metamaterial using graphene and vanadium oxide, which can efficiently absorb or transmit terahertz waves across a broad frequency range.

## Contribution

The novelty lies in the broadband tunability of the metamaterial through adjustments to graphene's Fermi energy and vanadium dioxide's conductivity.

## Key findings

- The metamaterial achieves over 90% absorptivity in the 2.05–14.03 THz range under specific conductivity and Fermi energy conditions.
- Adjusting graphene's Fermi energy narrows the high absorption range to 4.07–13.80 THz.
- The metamaterial shows high transmissivity exceeding 80% in the 15 THz range when vanadium dioxide conductivity is 200 S/m.

## Abstract

Terahertz waves have great potential for applications in security imaging, wireless communication, and other fields, but efficient and tunable terahertz-absorbing devices are the key to their technological development. In this paper, a tunable terahertz metamaterial based on graphene and vanadium dioxide materials is proposed. When the vanadium dioxide conductivity is 1.6 × 105 S/m and the Fermi energy level of graphene is 0.75 eV, the metamaterial exhibits high absorptivity exceeding 90% in ultra-broadband of 2.05–14.03 THz; when the Fermi energy level of graphene is adjusted to 0 eV, the high absorption wavelength range narrowed to 4.07–13.80 THz; when the vanadium dioxide conductivity is adjusted to 200 S/m, the metamaterial exhibits high transmissivity exceeding 80% in the wavelength range up to 15 THz. Additionally, the metamaterial is insensitive to polarization angles and incident angles, allowing it to adapt to changes in the angle of incidence and polarization in practical applications. The metamaterial has potential applications in optical switches, electromagnetic wave stealth devices, and filtering devices.