engleski

INTERACTIONS OF CHARGED PARTICLES WITH DOUBLE-LAYER GRAPHENE

Nowadays we are witnesses of a development of one promising branch of applied physics, called plasmonics. Especially interesting issue is plasmon- ics in quasi-two-dimensional (q2D) crystals deposited on various dielectric substrates. Here arise the main questions: how to increase the 2D plasmon propagation length and how to excite 2D plasmon most efficiently. We will focus on describing the interaction between electronic excitations in two graphene layers with phonons in aluminium oxide (Al2 O3 ) slab on which the graphene layers are deposited. Special attention will be paid to explain the hybridization between 2D plasmons and surface (TO) phonons. Because of multiple intersections of 2D plasmons and TO phonons the 2D plasmon moves to lower energies which allows it to be excited by charged particles moving at subthreshold speeds, v < vF. We will present the results for wake potential induced by a charged particle which moves parallel to the graphene/dielectric interface. It will be shown how various substrates mod- ify the efficiency of particle/plasmon coupling. The electronic excitations in graphene are obtained by using plane wave ab initio approach where we have addressed the problem of calculation of EELS spectra in the optical limit (Q→0) and how to avoid intersupercell Coulomb interaction.

double-layer graphene; electron energy loss spectra; stopping power

nije evidentirano