Effect of defects on the quasiparticle spectra of graphite and graphene

Abstract

It is shown that in graphite the spectral density of phonons polarized along the c axis has a V shaped feature similar to the so-called Dirac singularity characteristic of the electron density of states in graphene. The formation of quasilocal states, which increase the occupation of the quasiparticle levels near this feature, is analyzed from a unified standpoint for the phonon spectrum of metal-intercalated graphite and the electronic spectrum of graphene with vacancies. It is determined that in the electronic spectrum of graphene with an isolated vacancy quasilocal states are characteristic only of atoms belonging to the sublattice that does not contain this vacancy.

Quasi-Particle Spectra on Substrate and Embedded Graphene Monolayers

“…This was proved in (Feher et al, 2009) by using the formula obtained in (Kotlyar & Feodosyev, 2006), which relates an arbitrary matrix element of the Green's function ( ) ε ε = , but the magnitude of this change is in the order of the interaction, which is small. The surface roughness of the substrate may cause the anisotropy of the interatomic interaction, since the overlap integrals ik J will be different for the interaction of the same atom with its various neighbours.…”

“…4, showing the local density ( ) ,i ρ ε of states for the nearest, second, seventh and tenth neighbours of vacancies (Feher et al, 2009). …”

“…The interaction of metal atoms within one layer will be considered as a central force, i.e. matrices of force constants have form given in (Feher et al, 2009). The distance between nearest atoms of metal and carbon is equal to Fig.…”

Low-temperature vibration characteristics in InSe single crystals intercalated by Ni

“…Besides, it will not only change the force constants describing the interaction between the atoms in the van der Waals gap shores (as it happens in graphite or niobium diselenide [35]), but will also of describe the interlayer interaction between atoms in "sandwich" (both the interlayer and intralayer interaction). The reconstruction of the structure and interatomic interactions may be different for different concentrations of the intercalant, which casts doubt on the possibility of restoring the force constants ac- cording to acoustic, optical, and neutron experiments.…”

Electronic structure and magnetic properties of graphite intercalated with 3d-metals

“…Graphite is well known and investigated for decades material due to its quasi-two-dimensional structure, which gives rise to highly anisotropic electronic properties and provides an exciting avenue for testing physical concepts in lower dimensions [1][2][3]. Graphene, a single layer of graphite with two-dimensional structure and unique physical properties, recently emerged as one of the most promising lowdimensional nanomaterials [4,5].…”