Anisotropic Flow Control and Gate Modulation of Hybrid Phonon-Polaritons. Academic Article uri icon

abstract

  • Light-matter interaction in two-dimensional photonic or phononicmaterials allows for the confinement and manipulation of free-space radiation at sub-wavelength scales. Most notably, the van der Waals heterostructure composed of graphene (G) and hexagonal boron nitride (hBN) provides for gate-tunable hybrid hyperbolic plasmon phonon-polaritons (HP3). Here, we present the anisotropic flow control and gate-voltage modulation of HP3 modes in G-hBN on an air-Au microstructured substrate. Using broadband infrared synchrotron radiation coupled to a scattering-type near-field optical microscope, we launch HP3 waves in both hBN Reststrahlen bands and observe directional propagation across in-plane heterointerfaces created at the air-Au junction. TheHP3 hybridization is modulated by varying the gate voltage between graphene and Au. This modifies the coupling of continuum graphene plasmons with the discrete hBN hyperbolic phonon polaritons, which is described by an extended Fano model. This work representsthe first demonstration of the control of polariton propagation, introducing a theoretical approach to describe the breakingof the reflection and transmission symmetry for HP3 modes. Our findings augment the degree of control of polaritons in G-hBN and related hyperbolic metamaterial nanostructures, bringing new opportunities for on-chip nano-optics communication and computing.

published proceedings

  • Nano Lett

author list (cited authors)

  • Maia, F., O'Callahan, B. T., Cadore, A. R., Barcelos, I. D., Campos, L. C., Watanabe, K., ... Freitas, R. O.

citation count

  • 25

complete list of authors

  • Maia, Francisco CB||O'Callahan, Brian T||Cadore, Alisson R||Barcelos, Ingrid D||Campos, Leonardo C||Watanabe, Kenji||Taniguchi, Takashi||Deneke, Christoph||Belyanin, Alexey||Raschke, Markus B||Freitas, Raul O

publication date

  • February 2019