Related papers: On the universal AC optical background in graphene
We compute the optical conductivity of graphene beyond the usual Dirac cone approximation, giving results that are valid in the visible region of the conductivity spectrum. The effect of next nearest neighbor hoping is also discussed. Using…
Electronic properties of materials are commonly described by quasiparticles that behave as non-relativistic electrons with a finite mass and obey the Schroedinger equation. Here we report a condensed matter system where electron transport…
A ballistic strip of graphene (width W>> length L) connecting two normal metal contacts is known to have a minimum conductivity of 4e^{2}/pi h at the Dirac point of charge neutrality. We calculate what happens if one of the two contacts…
Optical reflectivity and transmission measurements over photon energies between 0.2 and 1.2 eV were performed on single-crystal graphene samples on a transparent SiO2 substrate. For photon energies above 0.5 eV, graphene yielded a…
Minimal conductivity of a single undoped graphene layer is known to be of the order of the conductance quantum, independent of the electron velocity. We show that this universality does not survive electron-electron interaction which…
We investigate the minimum conductivity of graphene within a quasiclassical approach taking into account electron-hole coherence effects which stem from the chiral nature of low energy excitations. Relying on an analytical solution of the…
We calculate the conductivity of a clean graphene sheet at finite temperatures starting from the tight-binding model. We obtain a finite value for the dc-conductivity at zero temperature. For finite temperature, the spontaneous…
Peculiar electronic properties of graphene, including the universal dc conductivity and the pseudodiffusive shot noise, are usually attributed to a small vicinity of the charge-neutrality point, away from which electron's effective mass…
The Hubbard model on the honeycomb lattice describes charge carriers in graphene with short range interactions. While the interaction modifies several physical quantities, like the value of the Fermi velocity or the wave function…
In this article, we investigate the temperature and chemical potential dependence of the optical conductivity of graphene, within a field theoretical representation in the continuum approximation, arising from an underlying tight-binding…
The impact of the electron-electron Coulomb interaction on the optical conductivity of graphene has led to a controversy that calls into question the universality of collisionless transport in this and other Dirac materials. Using a lattice…
We provide detailed calculation of the a.c. conductivity in the case of 1/r-Coulomb interacting massless Dirac particles in graphene in the collisionless limit when \omega >> T. The analysis of the electron self-energy, current vertex…
The independence of the dynamic conductivity of intrinsic graphene of frequency takes its origin in the compensation of the vanishing density of states by the diverging matrix element of the corresponding interband transition. The…
Following a nonperturbative formulation of strong-field QED developed in our earlier works, and using the Dirac model of the graphene, we construct a reduced QED_{3,2} to describe one species of the Dirac fermions in the graphene…
The minimal conductivity of graphene is a quantity measured in the DC limit. It is shown, using the Kubo formula, that the actual value of the minimal conductivity is sensitive to the order in which certain limits are taken. If the DC limit…
In this review we focus on the effect of the Dirac nature of graphene quasiparticles on two separate aspects. The first of these involves transport across superconducting graphene junctions with barriers of thickness $d_0$ and arbitrary…
The dynamical approach is applied to ballistic transport in mesoscopic graphene samples of length L and contact potential U. At times shorter than both relevant time scales, the flight time and \hslash/U, the major effect of the electric…
Since its discovery in 2004, graphene, a two-dimensional hexagonal carbon allotrope, has generated great interest and spurred research activity from materials science to particle physics and vice versa. In particular, graphene has been…
We present an analytic calculation of the conductivity of pure graphene as a function of frequency $\omega $, wave-vector $k$, and temperature for the range where the energies related to all these parameters are small in comparison with the…
We study non-linear dc transport in graphene using a hydrodynamic approach and conclude that in clean samples the drift velocity saturates at a weakly density-dependent value v_{sat} ~ 10^7 cm/s. We show that saturation results from the…