相关论文: Observation of Distinct Electron-Phonon Couplings …
We report multiphonon Raman scattering in graphene samples. Higher order combination modes involving 3 phonons and 4 phonons are observed in single-layer (SLG), bi-layer (BLG), and few layer (FLG) graphene samples prepared by mechanical…
Recent theory has demonstrated that the value of the electron-phonon coupling strength $\lambda$ can be extracted directly from the thermal attenuation (Debye-Waller factor) of Helium atom scattering reflectivity. This theory is here…
Raman spectroscopy is a fast, non-destructive means to characterize graphene samples. In particular, the Raman spectra show a significant dependence on doping. While the change in position and width of the G peak can be explained by the…
In contrary to the widely reported single and symmetric peak feature of G' (or 2D) band in Raman spectrum of graphene, we herein report the observation of splitting in G' band in free standing graphene. Our experimental findings provide a…
By analytically constructing the matrix elements of an electron-phonon interaction for the $D$ band in the Raman spectra of armchair graphene nanoribbons, we show that pseudospin and momentum conservation result in (i) a $D$ band consisting…
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…
We report a Raman spectroscopy study of graphene field-effect transistors (GFET) with a controlled amount of defects introduced in graphene by exposure to electron-beam irradiation. Raman spectra are taken at T = 8 K over a range of back…
We present low-temperature Raman measurements on gate tunable graphene encapsulated in hexagonal boron nitride, which allows to study in detail the Raman G and 2D mode frequencies and line widths as function of the charge carrier density.…
Our low-temperature magneto-Raman scattering measurements performed on graphene-like locations on the surface of bulk graphite reveal a new series of magneto-phonon resonances involving both K-point and Gamma-point phonons. In particular,…
We study electromagnetic properties of a double layer graphene system in which electrons from one layer are coupled with holes from the other layer. The gauge invariant linear response functions are obtained. The frequency dependences of…
The equilibrium optical phonons of graphene are well characterized in terms of anharmonicity and electron-phonon interactions, however their non-equilibrium properties in the presence of hot charge carriers are still not fully explored.…
We perform polarization-resolved Raman spectroscopy on graphene in magnetic fields up to 45T. This reveals a filling-factor-dependent, multi-component anticrossing structure of the Raman G peak, resulting from magnetophonon resonances…
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…
We have revisited the still unresolved puzzle of the dispersion of the Raman disordered-induced D band as a function of laser excitation photon energy E$_L$ in graphite-like materials. We propose that the D-mode is a combination of an optic…
We study the thermal distribution of intervalley phonons in a graphene sheet. These phonons have two components with the same frequency. The degeneracy of the two modes is preserved by weak electron-phonon coupling. A sufficiently strong…
We have performed electronic-structure and lattice-dynamics calculations on the AB and AA structures of bilayer graphene. We study the effect of external electric fields and compare results obtained with different levels of theory to…
The possibility of superconducting pairing of electrons in doped graphene due to in-plane and out-of-plane phonons is studied. Quadratic coupling of electrons with out-of-plane phonons is considered in details, taking into account both…
The electron-phonon coupling in potassium-doped graphene on Ir(111) is studied via the renormalization of the pi* band near the Fermi level, using angle-resolved photoemission spectroscopy. The renormalization is found to be fairly weak and…
Using density functional theory calculations we investigate the electronic structure of graphene doped by deposition of foreign atoms. We demonstrate that, as the charge transfer to the graphene layer increases, the band structure of the…
In this work, we study the Raman spectra of twisted bilayer graphene samples as a function of their twist-angles ($\theta$), ranging from 0.03$^\circ$ to 3.40$^\circ$, where local $\theta$ are determined by analysis of their associated…