"Production of plasmons in two layers of graphene with different doping densities traversed by swift electrons" NANOSMAT 2017 Special Issue

K. AKBARI; S. SEGUI; J. L. GERVASONI; Z. L. MISKOVIC; N. R. ARISTA

APPLIED SURFACE SCIENCE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018

0169-4332

We apply a fully relativistic formulation to calculate the average number of plasmonsexcited by an energetic electron traversing two parallel graphene layers separatedby a given distance d. We use a Drude model in the non-dissipative limit todescribe the conductivity of each layer in the THz frequency range, and addressthe general case in which the layers have different doping densities of chargecarriers by defining an asymmetry parameter. With this, we obtain the probabilitydensity of exciting the hybridized Dirac Plasmon-Polariton modes that resultfrom the coupling of the layers, and hence the number of plasmons excited by thepassing electron along its trajectory. We analyze the effect of different parameters,such as the interlayer distance, the incident particle velocity, and the asymmetryin doping densities. In particular, we find a cusp-like behaviour for nearly equalconductivities, that indicates a high sensitivity of the system to slight variations indoping densities.