Display options
Share it on

Nat Nanotechnol. 2015 Aug;10(8):682-6. doi: 10.1038/nnano.2015.131. Epub 2015 Jun 22.

Graphene on hexagonal boron nitride as a tunable hyperbolic metamaterial.

Nature nanotechnology

S Dai, Q Ma, M K Liu, T Andersen, Z Fei, M D Goldflam, M Wagner, K Watanabe, T Taniguchi, M Thiemens, F Keilmann, G C A M Janssen, S-E Zhu, P Jarillo-Herrero, M M Fogler, D N Basov

Affiliations

  1. Department of Physics, University of California, San Diego, La Jolla, California 92093, USA.
  2. Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02215, USA.
  3. 1] Department of Physics, University of California, San Diego, La Jolla, California 92093, USA [2] Department of Physics, Stony Brook University, Stony Brook, New York 11794-3800, USA.
  4. National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan.
  5. Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA.
  6. Ludwig-Maximilians-Universität and Center for Nanoscience, 80539 München, Germany.
  7. Micro and Nano Engineering Lab, Department of Precision and Microsystems Engineering, TU Delft, Mekelweg 2, 2628 CD Delft, The Netherlands.

PMID: 26098228 DOI: 10.1038/nnano.2015.131

Abstract

Hexagonal boron nitride (h-BN) is a natural hyperbolic material, in which the dielectric constants are the same in the basal plane (ε(t) ≡ ε(x) = ε(y)) but have opposite signs (ε(t)ε(z) < 0) in the normal plane (ε(z)). Owing to this property, finite-thickness slabs of h-BN act as multimode waveguides for the propagation of hyperbolic phonon polaritons--collective modes that originate from the coupling between photons and electric dipoles in phonons. However, control of these hyperbolic phonon polaritons modes has remained challenging, mostly because their electrodynamic properties are dictated by the crystal lattice of h-BN. Here we show, by direct nano-infrared imaging, that these hyperbolic polaritons can be effectively modulated in a van der Waals heterostructure composed of monolayer graphene on h-BN. Tunability originates from the hybridization of surface plasmon polaritons in graphene with hyperbolic phonon polaritons in h-BN, so that the eigenmodes of the graphene/h-BN heterostructure are hyperbolic plasmon-phonon polaritons. The hyperbolic plasmon-phonon polaritons in graphene/h-BN suffer little from ohmic losses, making their propagation length 1.5-2.0 times greater than that of hyperbolic phonon polaritons in h-BN. The hyperbolic plasmon-phonon polaritons possess the combined virtues of surface plasmon polaritons in graphene and hyperbolic phonon polaritons in h-BN. Therefore, graphene/h-BN can be classified as an electromagnetic metamaterial as the resulting properties of these devices are not present in its constituent elements alone.

References

  1. Nat Commun. 2015 Apr 22;6:6963 - PubMed
  2. Nat Commun. 2014 Aug 26;5:4782 - PubMed
  3. Opt Express. 2006 Sep 4;14(18):8247-56 - PubMed
  4. Science. 2011 Jun 10;332(6035):1291-4 - PubMed
  5. Nat Mater. 2015 Apr;14(4):421-5 - PubMed
  6. Phys Rev Lett. 2014 Aug 1;113(5):055502 - PubMed
  7. Nat Nanotechnol. 2014 Oct;9(10):768-79 - PubMed
  8. Nat Commun. 2014 Oct 17;5:5221 - PubMed
  9. Nat Mater. 2007 Dec;6(12):946-50 - PubMed
  10. Science. 2007 Mar 23;315(5819):1686 - PubMed
  11. Nature. 2013 Jul 25;499(7459):419-25 - PubMed
  12. Science. 2014 Mar 7;343(6175):1125-9 - PubMed
  13. Nat Nanotechnol. 2011 Sep 04;6(10):630-4 - PubMed
  14. Nature. 2012 Jul 5;487(7405):77-81 - PubMed
  15. Nano Lett. 2011 Nov 9;11(11):4701-5 - PubMed
  16. Nat Commun. 2015 Jun 26;6:7507 - PubMed
  17. Nano Lett. 2014 Jul 9;14(7):3876-80 - PubMed
  18. Nano Lett. 2015 May 13;15(5):3172-80 - PubMed
  19. Nature. 2012 Jul 5;487(7405):82-5 - PubMed
  20. ACS Nano. 2014 Nov 25;8(11):11305-12 - PubMed
  21. Nano Lett. 2014 Jan 8;14(1):299-304 - PubMed

Publication Types