Graphene Plasmonic Heterostructures for Terahertz Device Applications
Taiichi Otsuji, Akira Satou, Stephane Boubanga Tombet, Victor Ryzhii,
RIEC: Research Institute of Electrical Communication Tohoku University
Sendai, Japan otsuji@riec.tohoku.ac.jp
Vyacheslav V. Popov
Kotelnikov Institute of Radio Eng. and Electron. (Saratov Branch) Russian Academy of Sciences
Saratov, Russia Michael S. Shur Depts. of ECSE and PAPA Rensselaer Polytechnic Institute
Troy, USA (Invited)
Abstract—This paper reviews recent advances in graphene plasmonic heterostructures for terahertz (THz) device applica- tions. A double graphene-layer (DGL) core-shell structure with a tunnel-barrier layer is sandwiched between the outer gate stack layers at both sides. When the band offset is aligned to the THz photon energy, the DGL structure can mediate photon-assisted resonant tunneling, resulting in resonant emission or detection of the THz radiation. The cooperative double-resonant excitation with structure-sensitive graphene plasmons gives rise to various functionalities in the THz device implementations.
Keywords—graphene; plasmon; heterostructure; terahertz;
resonant tunneling; laser; photomixer; filter; detector; modulator I. INTRODUCTION
The two-dimensional Dirac Fermion systems in graphene yield unique plasmonic properties and mediate extraordinary strong light-matter interactions [1] The plasmonic modes properly defined by the structure- and bias-dependent dielec- tric/conductive properties of graphene enable various function- al signal-processing in the terahertz (THz) frequency range [2- 7]. This paper reviews recent advances in the graphene plas- monic heterostructures for THz device applications.
II. GRAPHENE PLASMONIC HETEROSTRUCTURES
A double graphene-layer (DGL) core-shell structure with a tunnel-barrier layer is sandwiched between the outer gate stack layers at both sides (Fig. 1). When the band offset energy is equalized to the THz photon energy, this structure can mediate photon-assisted resonant tunneling, resulting in the resonant emission and detection of the THz radiation (Fig. 1). Due to the nonlinear plasmonic metamaterial nature and ultrafast carrier- phonon-plasmon dynamics in graphene, the graphene plasmon modes matching the resonant tunneling enable the ‘double- resonant’ excitation, providing various functionalities, such as detection [3], amplification [4], superradiant plasmonic lasing [5], photomixing [6], tunable filtering, and high-speed modula- tion [7] of the THz radiation.
III. CONCLUSION
Cooperative double-resonant excitation of photon-assisted resonant tunneling and graphene plasmon modes in the pro- posed graphene heterostructures gives rise to various smart
THz device implementations.
ACKNOWLEDGMENT
The authors thank T. Watanabe, M. Ryzhii, A.A. Dubinov, V.
Ya Aleshkin, D. Fateev, and V. Mitin for their contributions. This work was supported by JST-CREST, JSPS-GA-SPR, Japan, RFBR and RAS, Russia, and the Army Research Lab., USA.
REFERENCES
[1] A.N. Grigorenko, M. Polini, and K.S. Novoselov, “Graphene plasmonics,”
Nature Photon,.vol. 6, pp. 749–758, 2012.
[2] T. Otsuji, V. Popov, and V. Ryzhii, “Active graphene plasmonics for terahertz device applications,” J. Phys. D., vol. 47, pp. 094006-1-10, 2014.
[3] V. Ryzhii, T. Otsuji, M. Ryzhii, and M.S. Shur, "Double graphene-layer plasma resonances terahertz detector," J. Phys. D, vol. 45, pp. 302001-1-6, 2012.
[4] T. Watanabe, T. Fukushima, Y. Yabe, S.A. Boubanga Tombet, A. Satou, A.A. Dubinov, V. Ya Aleshkin, V. Mitin, V. Ryzhii, and T. Otsuji, “Gain enhancement effect of surface plasmon polaritons on terahertz stimulated emission in optically pumped monolayer graphene,” New J. Phys., vol. 15, pp.
075003-1-11, 2013.
[5] V.V. Popov, O.V. Polischuk, A.R. Davoyan, V. Ryzhii, T. Otsuji, and M.S.
Shur, “Plasmonic terahertz lasing in an array of graphene nanocavities,” Phys.
Rev. B, vol. 86, pp. 195437-1-6, 2012.
[6] V. Ryzhii, M. Ryzhii , V. Mitin , M.S. Shur , A. Satou , and T. Otsuji,
"Terahertz photomixing using plasma resonances in double-graphene layer structures," J. Appl. Phys., vol. 113, pp. 174506-1-7, 2013.
[7] V. Ryzhii, T. Otsuji, M. Ryzhii, V. G. Leiman, S. O. Yurchenko, V. Mitin, and M. S. Shur, "Effect of plasma resonances on dynamic characteristics of double graphene-layer optical modulator," J. Appl. Phys., vol. 102, pp.
104507-1-7, 2012.
Fig. 1. A graphene plasmonic heterostructure for THz functional devices.