Plasmon-Acoustic Transducers Based on Graphene - 2D Boron Nitride Structures for Terahertz Frequency Range
Graphene and isomorphic to it 2D hexagonal boron nitride are the promising materials for using in nanoacoustics. Therefore, a more detailed study on the possibilities of creating the Plasmon-acoustic transducers for nanoacoustics with corresponding numerical estimates of their technical characteristics is urgent. In the paper, theoretically and by numerical estimates the fundamental possibility of Plasmon-acoustic transducers creating for nanoacoustic devices, operating in the terahertz frequency range has been justified. As the model being analyzed is a Plasmon-acoustic transducer, consisting of two subsystems: piezoelectric and Plasmon-polaritonic one, has been studied. The piezoelectric subsystem is made in the form of hexagonal boron nitride nanoribbon - a sound wire, the end part of which serves as a piezoelectric transduecer, exciting the elastic waves of terahertz range in the sound wire. The sound wire overlaps with the Plasmon-polaritonic subsystem in the form of a graphene nanoribbon, in which the surface plasmon-polaritons of TM polarization propagate. The introduced electrical impedance of the piezoelectric subsystem and the characteristic impedance have been calculated. It has been shown that their values are such, that it is possible to ensure optimal coordination of a load (sound wire) with Plasmon-polaritonic waveguide. It has been determined that graphene nanoplasmonics based on piezoelectric planar boron nitride are well combined with each other, which opens wide the opportunities for creating a new class of nanoelectronic devices.