Fizika Nizkikh Temperatur: Volume 43, Number 11 (November 2017), p. 1657-1668    ( to contents , go back )

Electron and phonon states localized near boundary of graphene

V.V. Eremenko, V.A. Sirenko, I.A. Gospodarev, E.S. Syrkin, S.B. Feodosyev, I.S. Bondar

B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
E-mail: feodosiev@ilt.kharkov.ua

A. Feher

Centre of Low Temperature Physics Faculty of Science P.J. Šafarik University & Institute of Experimental Physics SAS 9 Park Angelinum, Košice 04154, Slovakia

K.A. Minakova

National Technical University “Kharkiv Polytechnic Institute”, 21 Bahaliy Str., Kharkov 61002, Ukraine

Received June 20, 2017

Abstract

Analytical and numerical analysis was performed for an electron and phonon spectra evolution under formation of the boundary with “zigzag”-chirality. It is found an ex-citation of the wave with relativistic dispersion. The wave propagates along the boundary and decays with distance from it. The conditions of the occurrence of the wave and its properties are determined. It is shown, in particular, that the wave propagates over the atoms of sublattice, which incorporates those with bonds, broken during formation of the boundary. The local densities of states of the atoms of such sublattice gain sharp resonances due to gapped wave. It is found, that a formation on graphene layer of the boundary with given chirality has a similar effect on the phonon modes, which are polarized normally to the layer, and the sharp resonances are formed at frequencies in vicinity of quasiflexural ones at quasiwave vector in the K-point of the first Brillouin zone. In this way, appearance of the “zigzag”-boundary increases both the number of charge carriers and of phonons with high group velocity, which are able to produce significant contribution to electron-phonon coupling.

PACS: 63.22.–m Phonons or vibrational states in low-dimensional structures and nanoscale materials;
PACS: 63.22.Rc Phonons in graphene;
PACS: 63.20.kp Phonon-defect interactions;
PACS: 73.22.–f Electronic structure of nanoscale materials and related systems;
PACS: 73.22.Pr Electronic structure of graphene.

Key words: quasiparticle spectrum, nanostructures, graphene, defect, surface waves.

Published online: September 25, 2017

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