Ukrainian Journal of Physical Optics 

Home page
 
 

Other articles 

in this issue
THz response of nonequilibrium electrons of highly doped graphene on a polar substrate

Kukhtaruk S. M.

Download this article

Abstract. 
We consider high-frequency response of a system consisting of drifting electrons in a highly doped graphene and surface polar optical phonons of a polar substrate. We obtain the dielectric function, the frequencies and the decrement/increment of cooperative plasmon–optical phonon oscillations for this interacting system. We find that the response depends significantly on the degree of nonequilibrium for the electrons. In particular, the interaction between drifting plasmons and surface polar optical phonons leads to instability of the electron subsystem due to Vavilov–Cherenkov effect. We suggest that the hybrid system, a graphene on a polar substrate, is capable of using in amplifiers or generators of THz electromagnetic radiation.

Keywords: graphene, plasmon, optical phonon, instability, dielectric function

PACS: 72.80.Vp, 73.20.Mf, 71.38.-k, 71.45.Gm, 77.22.Ch
UDC:  535.58, 535.56, 537.5
Ukr. J. Phys. Opt. 14 24-30
doi: 10.3116/16091833/14/1/24/2013
Received: 01.11.2012

Анотація. Розглянуто надвисокочастотний відгук системи дрейфуючих електронів сильно легованого графену та поверхневих оптичних фононів полярної підкладки. Для взаємодіючої системи розраховано діелектричну функцію, частоти та декремент/інкремент спільних коливань. Показано, що відгук системи суттєво залежить від ступеня нерівноважності електронів. Зокрема, взаємодія між плазмонами та поверхневими оптичними фононами приводить до дрейфової нестійкості, зумовленої ефектом Вавілова–Черенкова. Розглянуту систему можна використовувати для генерації або підсилення терагерцового електромагнітного випромінювання
 

REFERENCES
  1. Castro Neto A H, Guinea F, Peres N M R, Novoselov K S and Geim A K, 2009. The elec-tronic properties of graphene. Rev. Mod. Phys. 81: 109–162. doi:10.1103/RevModPhys.81.109 
  2. Wallace P R, 1947. The band theory of graphite. Phys. Rev. 71: 622–634. http://dx.doi.org/10.1103/PhysRev.71.622 
  3. Efetov D K and Kim P, 2010. Controlling electron-phonon interactions in fraphene at ultra-high carrier densities. Phys. Rev. Lett. 105: 256805. doi:10.1103/PhysRevLett.105.256805 PMid:21231611 
  4. Fratini S and Guinea F, 2008. Substrate-limited electron dynamics in graphene. Phys. Rev. B. 77: 195415. doi:10.1103/PhysRevB.77.195415 
  5. Li X, Barry E A, Zavada J M, Buongiorno Nardelli M and Kim K W, 2010. Surface polar phonon dominated electron transport in graphene. Appl. Phys. Lett. 97: 232105. doi:10.1063/1.3525606 
  6. DaSilva A M, Zou K, Jain J K and Zhu J, 2010. Mechanism for current saturation and energy dissipation in graphene transistors. Phys. Rev. Lett. 104: 236601. doi:10.1103/PhysRevLett.104.236601 PMid:20867258 
  7. Perebeinos V and Avouris P, 2010. Inelastic scattering and current saturation in graphene. Phys. Rev. B. 81: 195442. doi:10.1103/PhysRevB.81.195442 
  8. Zou K, Hong X, Keefer D and Zhu J, 2010. Deposition of high-quality HfO2 on graphene and the effect of remote oxide phonon scattering. Phys. Rev. Lett. 105: 126601. doi:10.1103/PhysRevLett.105.126601 PMid:20867662 
  9. Konar A, Fang T and Jena D, 2010. Effect of high-κ gate dielectrics on charge transport in graphene-based field effect transistors. Phys. Rev. B. 82: 115452. doi:10.1103/PhysRevB.82.115452 
  10. Strikha M V, 2012. Non-volatile memory and IR radiation modulators based upon graphene-on-ferroelectric substrate. A review. Ukr. J. Phys. Opt., Suppl. 3. 13: S5–S26. doi:10.3116/16091833/13/1/S5/2012
  11. Jablan M, Buljan H and Soljačić M, 2009. Plasmonics in graphene at infrared frequencies. Phys. Rev. B. 80: 245435. doi:10.1103/PhysRevB.80.245435 
  12. Hwang E H, Sensarma R and Das Sarma S, 2010. Plasmon-phonon coupling in graphene. Phys. Rev. B. 82: 195406. doi:10.1103/PhysRevB.82.195406 
  13. Koch R J, Seyller Th and Schaefer J A, 2010. Strong phonon-plasmon coupled modes in the graphene/silicon carbide heterosystem. Phys. Rev. B. 82: 201413(R). doi:10.1103/PhysRevB.82.201413 
  14. Jablan M, Soljačić M and Buljan H, 2011. Unconventional plasmon-phonon coupling in gra-phene. Phys. Rev. B. 83: 161409(R). doi:10.1103/PhysRevB.83.161409 
  15. Fei Z, Andreev G O, Bao W, Zhang L M, McLeod A S, Wang C, Stewart M K, Zhao Z, Dominguez G, Thiemens M, Fogler M M, Tauber M J, Castro-Neto A H, Ning Lau C, Keil-mann F and Basov D N, 2011. Infrared nanoscopy of dirac plasmons at the graphene-SiO2 in-terface. Nano Lett. 11: 4701–5. doi:10.1021/nl202362d PMid:21972938 
  16. Kukhtaruk S M, 2008. High-frequency properties of systems with drifting electrons and polar optical phonons. Semicond. Phys., Quant. Electron. and Optoelectron. 11: 43–49. 
  17. Sydoruk O, Kalinin V and Solymar L, 2010. Terahertz instability of optical phonons interact-ing with plasmons in two-dimensional electron channels. Appl. Phys. Lett. 97: 062107. doi:10.1063/1.3479416 
  18. Li X, Barry E A, Zavada J M, Buongiorno Nardelli M and Kim K W, 2010. Influence of elec-tron-electron scattering on transport characteristics in monolayer grapheme. Appl. Phys. Lett. 97: 082101. doi:10.1063/1.3483612 
  19. Fang T, Konar A, Xing H and Jena D, 2011. High-field transport in two-dimensional gra-phene. Phys. Rev. B. 84: 125450. doi:10.1103/PhysRevB.84.125450 
  20. Born M and Huang K. Dynamical theory of crystal lattices. Oxford: Clarendon Press (1954). 
  21. Lowndes R P, 1972. Anharmonicity in the silver and thallium halides: far-infrared dielectric response. Phys. Rev. B. 6: 1490–1498. doi:10.1103/PhysRevB.6.1490 
  22. Lowndes R P, 1972. Anharmonicity in the silver and thallium halides: low-frequency dielec-tric response. Phys. Rev. B. 6: 4667–4674. doi:10.1103/PhysRevB.6.4667 
(c) Ukrainian Journal of Physical Optics