相关论文: Core level spectra in XPS of pristine and doped gr…
We calculate core-level spectra for pristine and doped free-standing graphene sheets. Instructions for how to perform the calculations are given in detail. Although pristine graphene is not metallic the core-level spectrum presents…
We derive core-level spectra for doped free-standing bilayer graphene. Numerical results are presented for all nine combinations of the doping concentrations $10^{12}\rm{cm}^{-2}$, $10^{13}\rm{cm}^{-2}$, and $10^{14}\rm{cm}^{-2}$ in the two…
A doped graphene layer in the integer quantum Hall regime reveals a highly unusual particle-hole excitation spectrum, which is calculated from the dynamical polarizability in the random phase approximation. We find that the elementary…
We develop a method of the ab-initio calculation for the core-level x-ray photoemission spectroscopy (XPS). By calculating one-electron states in the presence of core-hole potential, excited states are constructed by distributing electrons…
X-ray photoelectron spectroscopy (XPS) combined with first principles modeling is a powerful tool for determining the chemical composition and electronic structure of novel materials. Of these, graphene is an especially important model…
The core-level electronic structures of the exfoliated graphene sheets on a Au-coated SiOx substrate have been studied by synchrotron radiation photoelectron spectroscopy (SR-PES) on a micron-scale. The graphene was firstly demonstrated its…
Density functional theory calculations suggest a pronounced hole electron doping asymmetry in a single layer graphene. It turns out that a single graphene sheet can sustain doping levels up to 0.1 holes or up to a remarkably large 1.9…
Excitation of surface plasmons supported by doped graphene sheets at terahertz frequencies is investigated numerically. To alleviate the momentum mismatch between the highly-confined plasmon modes and the incident radiation, it is proposed…
We have performed first-principles calculations to study optical absorption spectra of doped graphene with many-electron effects included. Both self-energy corrections and electron-hole interactions are reduced due to the enhanced screening…
Core level binding energies and absorption edges are at the heart of many experimental techniques concerned with element-specific structure, electronic structure, chemical reactivity, elementary excitations and magnetism. X-ray…
Core hole photoemission (XPS) provides a powerful indirect probe of the low energy excitations of a many electron system. We argue that XPS can be used to study the way in which a gap opens at a metal-superconductor or metal- insulator…
The particle-hole excitation spectrum for doped graphene is calculated from the dynamical polarizability. We study the zero and finite magnetic field cases and compare them to the standard two-dimensional electron gas. The effects of…
We consider graphene in a strong perpendicular magnetic field at zero temperature with an integral number of filled Landau levels and study the dispersion of single particle-hole excitations. We first analyze the two-body problem of a…
In monolayer graphene, substitutional doping during growth can be used to alter its electronic properties. We used scanning tunneling microscopy (STM), Raman spectroscopy, x-ray spectroscopy, and first principles calculations to…
Graphene is a realization of an esoteric class of materials -- electronic crystalline membranes. We study the interplay between the free electrons and the two-dimensional crystal, and find that it induces a substantial effect on the elastic…
Near-interfacial oxide traps and chemical impurities on the graphene surface or at the graphene-dielectric interface can be a source of intentional or unintentional doping of graphene sheet. The efficiency of such chemical doping can vary…
We calculate the real and imaginary electron self-energy as well as the quasiparticle spectral function in doped graphene taking into account electron-electron interaction in the leading order dynamically screened Coulomb coupling. Our…
Graphene phonons are measured as a function of electron doping via the addition of potassium adatoms. In the low doping regime, the in-plane carbon G-peak hardens and narrows with increasing doping, analogous to the trend seen in graphene…
X-ray photoelectron spectroscopy of graphene is important both for its characterization and as a model for other carbon materials. Despite great recent interest, the intrinsic photoemission of its single layer has not been unambiguously…
The modification of single layer graphene due to intense, picoseconds near-infrared laser pulses is investigated. We monitor the stable changes introduced to graphene upon photoexcitation using Raman spectroscopy. We find that…