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Related papers: Electron-Phonon Interactions for Optical Phonon Mo…

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Few-layer graphene is a layered carbon material with covalent bonding in the layers and weak van der Waals interactions between the layers. The interlayer energy is more than two orders of magnitude smaller than the intralayer one, which…

Mesoscale and Nanoscale Physics · Physics 2014-12-24 Valentin N. Popov , Christian Van Alsenoy

We demonstrate that graphite phonon dispersions have two Kohn anomalies at the Gamma-E_2g and K-A'1 modes. The anomalies are revealed by two sharp kinks. By an exact analytic derivation, we show that the slope of these kinks is proportional…

Materials Science · Physics 2010-09-03 S. Piscanec , M. Lazzeri , F. Mauri , A. C. Ferrari , J. Robertson

Quasi free-standing monolayer graphene can be produced by intercalating species like oxygen or hydrogen between epitaxial graphene and the substrate crystal. If the graphene is indeed decoupled from the substrate, one would expect the…

Collective excitations of coupled electron-phonon systems are calculated for both monolayer and bilayer graphene, taking into account the non-perturbative Coulomb coupling between electronic excitations in graphene and the substrate…

Mesoscale and Nanoscale Physics · Physics 2010-11-12 E. H. Hwang , Rajdeep Sensarma , S. Das Sarma

The phonon dispersion of graphene on Ir(111) has been determined by means of angle-resolved inelastic electron scattering and density functional calculations. Kohn anomalies of the highest optical-phonon branches are observed at the…

Materials Science · Physics 2015-06-17 M. Endlich , A. Molina-Sánchez , L. Wirtz , J. Kröger

Electron-phonon coupling (EPC) in bilayer graphene (BLG) at different doping levels is studied by first-principles calculations. The phonons considered are long-wavelength high-energy symmetric (S) and antisymmetric (AS) optical modes. Both…

Materials Science · Physics 2013-03-26 Jia-An Yan , K. Varga , M. Y. Chou

Phonons, the fundamental vibrational modes of a crystal lattice, play a crucial role in determining electronic properties of materials through electron-phonon interaction. However, it has proved difficult to directly probe the phonon modes…

Materials Science · Physics 2019-09-04 Yu Zhang , Qian Yang , Lin He

We analyze the effects of an electron-phonon interaction on the one-electron spectral weight A(k,omega) of a d_{x^2-y^2} superconductor. We study the case of an Einstein phonon mode with various momentum-dependent electron-phonon couplings…

Superconductivity · Physics 2009-11-10 A. W. Sandvik , D. J. Scalapino , N. E. Bickers

The search of new means of generating and controlling topological states of matter is at the front of many joint efforts, including bandgap engineering by doping and light-induced topological states. Most of our understading, however, is…

Mesoscale and Nanoscale Physics · Physics 2018-07-19 Hernan L. Calvo , Javier S. Luna , Virginia Dal Lago , Luis E. F. Foa Torres

The discovery of an enhanced superconducting transition temperature $T_c$ in monolayers of FeSe grown on several oxide substrates has opened a new route to high-$T_c$ superconductivity through interface engineering. One proposal for the…

Superconductivity · Physics 2017-08-23 Yan Wang , Louk Rademaker , Elbio Dagotto , Steven Johnston

We determine from first-principles the finite-temperature properties--linewidths, line shifts, and lifetimes--of the key vibrational modes that dominate inelastic losses in graphitic materials. In graphite, the phonon linewidth of the…

Materials Science · Physics 2007-10-25 Nicola Bonini , Michele Lazzeri , Nicola Marzari , Francesco Mauri

Gate-modulated low-temperature Raman spectra reveal that the electric field effect (EFE), pervasive in contemporary electronics, has marked impacts on long wavelength optical phonons of graphene. The EFE in this two dimensional honeycomb…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Jun Yan , Yuanbo Zhang , Philip Kim , Aron Pinczuk

Modeling spin-wave (magnon) dynamics in novel materials is important to advance spintronics and spin-based quantum technologies. The interactions between magnons and lattice vibrations (phonons) limit the length scale for magnon transport.…

We calculate hybridization of plasmons and intrinsic optical phonons in graphene by using the self-consistent linear response formalism. We find that longitudinal plasmons (transverse magnetic modes) couple exclusively to transverse optical…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 M. Jablan , M. Soljačić , H. Buljan

We report a comprehensive micro-Raman scattering study of electrochemically-gated graphene field-effect transistors. The geometrical capacitance of the electrochemical top-gates is accurately determined from dual-gated Raman measurements,…

Mesoscale and Nanoscale Physics · Physics 2016-08-08 Guillaume Froehlicher , Stéphane Berciaud

We develop a theory for the electron-phonon interaction effects on the electronic properties of graphene. We analytically calculate the electron self-energy, spectral function and band velocity renormalization due to phonon-mediated…

Materials Science · Physics 2009-11-13 Wang-Kong Tse , S. Das Sarma

We report on a theoretical study of the influence of electron-electron interactions on ARPES spectra in graphene that is based on the random-phase-approximation and on graphene's massless Dirac equation continuum model. We find that level…

Mesoscale and Nanoscale Physics · Physics 2008-03-03 Marco Polini , Reza Asgari , Giovanni Borghi , Yafis Barlas , T. Pereg-Barnea , A. H. MacDonald

We describe a peculiar fine structure acquired by the in-plane optical phonon at the Gamma-point in graphene when it is brought into resonance with one of the inter-Landau-level transitions in this material. The effect is most pronounced…

Mesoscale and Nanoscale Physics · Physics 2009-09-24 M. O. Goerbig , J. -N. Fuchs , K. Kechedzhi , Vladimir I. Fal'ko

Radio-frequency compressed ultrafast electron diffraction has been used to probe the coherent and incoherent coupling of impulsive electronic excitation at 1.55 eV (800 nm) to optical and acoustic phonon modes directly from the perspective…

Materials Science · Physics 2015-06-23 Robert P. Chatelain , Vance R. Morrison , Bart L. M. Klarenaar , Bradley J. Siwick

We theoretically investigated phonon dispersion in AA-stacked, AB-stacked and twisted bilayer graphene with various rotation angles. The calculations were performed using the Born-von-Karman model for the intra-layer atomic interactions and…

Mesoscale and Nanoscale Physics · Physics 2013-07-19 Alexandr I. Cocemasov , Denis L. Nika , Alexander A. Balandin