The extraordinary electronic properties of graphene provided the main thrusts for the rapid advance of graphene electronics1. In photonics, the gate-controllable electronic properties of graphene provide a route to efficiently manipulate the interaction of photons with graphene, which has recently sparked keen interest in graphene plasmonics2,3,4,5,6,7,8,9,10. However, the electro-optic tuning capability of unpatterned graphene alone is still not strong enough for practical optoelectronic applications owing to its non-resonant Drude-like behaviour. Here, we demonstrate that substantial gate-induced persistent switching and linear modulation of terahertz waves can be achieved in a two-dimensional metamaterial11,12, into which an atomically thin, gated two-dimensional graphene layer is integrated. The gate-controllable light–matter interaction in the graphene layer can be greatly enhanced by the strong resonances of the metamaterial13. Although the thickness of the embedded single-layer graphene is more than six orders of magnitude smaller than the wavelength (<λ/1,000,000), the one-atom-thick layer, in conjunction with the metamaterial, can modulate both the amplitude of the transmitted wave by up to 47% and its phase by 32.2° at room temperature. More interestingly, the gate-controlled active graphene metamaterials show hysteretic behaviour in the transmission of terahertz waves, which is indicative of persistent photonic memory effects.
This is a preview of subscription content, access via your institution
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Get just this article for as long as you need it
Prices may be subject to local taxes which are calculated during checkout
Geim, A. K. & Novoselov, K. S. The rise of graphene. Nature Mater. 6, 183–191 (2007).
Wang, F. et al. Gate-variable optical transitions in graphene. Science 320, 206–209 (2008).
Bonaccorso, F., Sun, Z., Hasan, T. & Ferrari, A. C. Graphene photonics and optoelectronics. Nature Photon. 4, 611–622 (2010).
Ju, L. et al. Graphene plasmonics for tunable terahertz metamaterials. Nature Nanotech. 6, 630–634 (2011).
Koppens, F. H. L., Chang, D. E. & De Abajo, F. J. G. Graphene plasmonics: A platform for strong light–matter interactions. Nano Lett. 11, 3370–3377 (2011).
Liu, M. et al. A graphene-based broadband optical modulator. Nature 474, 64–67 (2011).
Vakil, A. & Engheta, N. Transformation optics using graphene. Science 332, 1291–1294 (2011).
Echtermeyer, T. J. et al. Strong plasmonic enhancement of photovoltage in graphene. Nature Commun. 2, 458 (2011).
Papasimakis, N. et al. Graphene in a photonic metamaterial. Opt. Express 18, 8353–8359 (2010).
Maeng, I. et al. Gate-controlled nonlinear conductivity of Dirac fermion in graphene field-effect transistors measured by terahertz time-domain spectroscopy. Nano Lett. 12, 551–555 (2012).
Pendry, J. B., Holden, A. J., Robbins, D. J. & Stewart, W. J. Magnetism from conductors and enhanced nonlinear phenomena. IEEE Trans. Microw. Theory Tech. 47, 2075–2084 (1999).
Smith, D. R., Padilla, W. J., Vier, D. C., Nemat-Nasser, S. C. & Schultz, S. Composite medium with simultaneously negative permeability and permittivity. Phys. Rev. Lett. 84, 4184–4187 (2000).
Choi, M. et al. A terahertz metamaterial with unnaturally high refractive index. Nature 470, 369–373 (2011).
Ferguson, B. & Zhang, X-C. Materials for terahertz science and technology. Nature Mater. 1, 26–33 (2002).
Hu, T., Padilla, W. J., Xin, Z. & Averitt, R. D. Recent progress in electromagnetic metamaterial devices for terahertz applications. IEEE J. Sel. Top. Quan. Electron. 17, 92–101 (2011).
Kleine-Ostmann, T., Dawson, P., Pierz, K., Hein, G. & Koch, M. Room-temperature operation of an electrically driven terahertz modulator. Appl. Phys. Lett. 84, 3555–3557 (2004).
Sensale-Rodriguez, B. et al. Unique prospects for graphene-based terahertz modulators. Appl. Phys. Lett. 99, 113104 (2011).
Chen, H. T. et al. Active terahertz metamaterial devices. Nature 444, 597–600 (2006).
Chen, H-T. et al. A metamaterial solid-state terahertz phase modulator. Nature Photon. 3, 148–151 (2009).
Shrekenhamer, D. et al. High speed terahertz modulation from metamaterials with embedded high electron mobility transistors. Opt. Express 19, 9968–9975 (2011).
Das, A. et al. Monitoring dopants by Raman scattering in an electrochemically top-gated graphene transistor. Nature Nanotech. 3, 210–215 (2008).
Efetov, D. K. & Kim, P. Controlling electron-phonon interactions in graphene at ultrahigh carrier densities. Phys. Rev. Lett. 105, 256805 (2010).
Wang, H. M., Wu, Y. H., Cong, C. X., Shang, J. Z. & Yu, T. Hysteresis of electronic transport in graphene transistors. ACS Nano 4, 7221–7228 (2010).
Echtermeyer, T. J. et al. Nonvolatile switching in graphene field-effect devices. IEEE Electron Device Lett. 29, 952–954 (2008).
Jeong, H. Y. et al. Graphene oxide thin films for flexible nonvolatile memory applications. Nano Lett. 10, 4381–4386 (2010).
Song, E. B. et al. Robust bi-stable memory operation in single-layer graphene ferroelectric memory. Appl. Phys. Lett. 99, 042109 (2011).
Driscoll, T. et al. Memory metamaterials. Science 325, 1518–1521 (2009).
Kim, K. S. et al. Large-scale pattern growth of graphene films for stretchable transparent electrodes. Nature 457, 706–710 (2009).
MartÍn-Moreno, L. et al. Theory of extraordinary optical transmission through subwavelength hole arrays. Phys. Rev. Lett. 86, 1114–1117 (2001).
Dawlaty, J. M. et al. Measurement of the optical absorption spectra of epitaxial graphene from terahertz to visible. Appl. Phys. Lett. 93, 131905 (2008).
Li, X. et al. Large-area synthesis of high-quality and uniform graphene films on copper foils. Science 324, 1312–1314 (2009).
Yu, Y-J. et al. Tuning the graphene work function by electric field effect. Nano Lett. 9, 3430–3434 (2009).
Ferrari, A. C. et al. Raman spectrum of graphene and graphene layers. Phys. Rev. Lett. 97, 187401 (2006).
Adam, S., Hwang, E. H., Galitski, V. M. & Das Sarma, S. A self-consistent theory for graphene transport. Proc. Natl Acad. Sci. USA 104, 18392–18397 (2007).
Fedotov, V. A., Rose, M., Prosvirnin, S. L., Papasimakis, N. & Zheludev, N. I. Sharp trapped-mode resonances in planar metamaterials with a broken structural symmetry. Phys. Rev. Lett. 99, 147401 (2007).
We thank B. H. Hong for the discussion on the application of graphene, Y-J. Yu for the discussion on carrier transport in graphene, J. H. Han for the characterization of graphene, and H. Choi for proofreading the manuscript. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2008-0062235, 2009-0069459, 2010-0012058, 2011-0020186 and 2011-0028151). S.S.L. acknowledges the support by the NRF of Korea grant funded by the MEST (No.2010-0027050). S-Y.C. acknowledges the GFR Program (2011-0031640) sponsored by the MEST. C-G.C. acknowledges the Nano R&D Program (2011-0019169) through the NRF of Korea funded by the MEST and the Creative Research Program of the ETRI (11YF1110). X.Z. acknowledges the support from the US Department of Energy under contract no. DE-AC02-05CH11231 through Materials Sciences Division of Lawrence Berkeley National Laboratory (LBNL).
The authors declare no competing financial interests.
Rights and permissions
About this article
Cite this article
Lee, S., Choi, M., Kim, TT. et al. Switching terahertz waves with gate-controlled active graphene metamaterials. Nature Mater 11, 936–941 (2012). https://doi.org/10.1038/nmat3433
This article is cited by
Nonvolatile reconfigurable terahertz wave modulator
Electrically tuneable terahertz metasurface enabled by a graphene/gold bilayer structure
Communications Materials (2022)
Fractal interwoven resonator based penta-band metamaterial absorbers for THz sensing and imaging
Scientific Reports (2022)
Vision, application scenarios, and key technology trends for 6G mobile communications
Science China Information Sciences (2022)
Applications of Tunable Mid-Infrared Plasmonic Square-Nanoring Resonator Based on Graphene Nanoribbon