The Tunable Hybrid Surface Phonon and Plasmon Polariton Modes in Boron   Nitride Nanotube and Graphene Monolayer Heterostructures
  The hybrid modes incorporating surface phonon polariton (SPhP) modes in boron nitride nanotubes (BNNTs) and surface plasmon polariton (SPP) modes in graphene monolayers are theoretically studied. The combination of the 1D BNNTs and 2D graphene monolayer further improves the modal characteristics with electrical tunability. Superior to the graphene monolayers, the proposed heterostructures supports single mode transmission with lateral optical confinement. The modal characteristics can be shifted from SPP-like toward SPhP-like. Both the figure of merit and field enhancement of hybrid modes are improved over 3 times than those of BNNT SPhP modes, which may further enable sub-wavelength mid-infrared applications. 
Yu Sun, Zheng Zheng, Jiangtao Cheng, Jiansheng Liu
physics.optics