On the universal AC optical background in graphene
نویسندگان
چکیده
The latest experiments have confirmed the theoretically expected universal value πe/2h of the ac conductivity of graphene and have revealed departures of the quasiparticle dynamics from predictions for the Dirac fermions in idealized graphene. We present analytical expressions for the ac conductivity in graphene which allow one to study how it is affected by interactions, temperature, external magnetic field and the opening of a gap in the quasiparticle spectrum. We show that the ac conductivity of graphene does not necessarily give a metrologically accurate value of the von Klitzing constant h/e, because it is depleted by the electron-phonon interaction. In a weak magnetic field the ac conductivity oscillates around the universal value and the Drude peak evolves into a peak at the cyclotron frequency. (Some figures in this article are in colour only in the electronic version) PACS numbers: 78.20.Ls, 73.43.Qt, 81.05.Uw Submitted to: New J. Phys. On the universal AC optical background in graphene 2
منابع مشابه
Effect of electron-phonon interaction on spectroscopies in graphene
We calculate the effect of the electron-phonon interaction on the electronic density of states DOS , the quasiparticle properties, and on the optical conductivity of graphene. In metals with DOS constant on the scale of phonon energies, the electron-phonon renormalizations drop out of the dressed DOS, however, due to the Dirac nature of the electron dynamics in graphene, the band DOS is linear ...
متن کاملEffects of optical and surface polar phonons on the optical conductivity of doped graphene
Using the Kubo linear response formalism, we study the effects of intrinsic graphene optical and surface polar phonons (SPPs) on the optical conductivity of doped graphene. We find that inelastic electron-phonon scattering contributes significantly to the phonon-assisted absorption in the optical gap. At room temperature, this midgap absorption can be as large as 20–25% of the universal ac cond...
متن کاملQuantum modeling of light absorption in graphene based photo-transistors
Graphene based optical devices are highly recommended and interested for integrated optical circuits. As a main component of an optical link, a photodetector based on graphene nano-ribbons is proposed and studied. A quantum transport model is presented for simulation of a graphene nano-ribbon (GNR) -based photo-transistor based on non-equilibrium Green’s function method. In the proposed model a...
متن کاملOptical absorption in graphene integrated on silicon waveguides
To fully utilize graphene’s remarkable optical properties for optoelectronic applications, it needs to be integrated in planar photonic systems. Here, we demonstrate integration of graphene on silicon photonic circuits and precise measurement of the optical absorption coefficient in a graphene/ waveguide hybrid structure. A method based on Mach-Zehnder interferometry is employed to achieve high...
متن کاملTransmission Properties of the Periodic Structures Based on Graphene Nonlinear Optical Conductivity in a Terahertz Field
By developing the terahertz (THz) technology, in addition to generators and detectors of THz waves, the existence of some tools such as modulators and filters are needed. THz filters are important tools for various applications in the field of chemical and biological sensors. Linear and nonlinear optical properties of the graphene have attracted lots of attention. In fact graphene exhibits vari...
متن کامل