相关论文: Third harmonic generation in graphene and few-laye…

We theoretically investigate the effects of Coulomb interaction, at the level of unscreened Hartree-Fock approximation, on third harmonic generation of undoped graphene in an equation of motion framework. The unperturbed electronic states…

High harmonic generation (HHG) is a widely explored process in solids, where intense lasers drive attosecond-to-femtosecond electron dynamics within bands, causing high-energy emission. While electrons and photons are considered the main…

An optical Second-Harmonic Generation (SHG) allows to probe various structural and symmetry-related properties of materials, since it is sensitive to the inversion symmetry breaking in the system. Here, we investigate the SHG response from…

The theory of optical effects in hydrogenated graphene (graphane) in terahertz and infrared range is developed, including the analysis of complex conductivity, reflection coefficient for graphane on a substrate and dispersion of surface…

We report that 30-inch scale multiple roll-to-roll transfer and wet chemical doping considerably enhance the electrical properties of the graphene films grown on roll-type Cu substrates by chemical vapor deposition. The resulting graphene…

We report a systematic study of the contact resistance present at the interface between a metal (Ti) and graphene layers of different, known thickness. By comparing devices fabricated on 11 graphene flakes we demonstrate that the contact…

Intense efforts have been made in recent years to realize nonlinear optical interactions at the single-photon level. Much of this work has focused on achieving strong third-order nonlinearities, such as by using single atoms or other…

Low-energy reflectivity of electrons from single- and multi-layer graphene is examined both theoretically and experimentally. A series of minima in the reflectivity over the energy range of 0 - 8 eV are found, with the number of minima…

We report optical second-harmonic generation (SHG) in reflection from GaSe crystals of 1 to more than 100 layers using a fundamental picosecond pulsed pump at 1.58 eV and a supercontinuum white light pulsed laser with energies ranging from…

A manifestation of electron-hole pairing in nonlinear electromagnetic response of a double layer graphene system is studied. It is shown that the pairing causes the appearance of a number of peaks in the frequency dependence of the…

Despite having outstanding electrical properties, graphene is unsuitable for optical devices because of its zero band gap. Here, we report two-dimensional excitonic photoluminescence (PL) from graphene grown on Cu(111) surface, which shows…

The crystallographic symmetries and spatial distribution of stacking domains in graphene films on SiC have been studied by low energy electron diffraction (LEED) and dark field imaging in a low energy electron microscope (LEEM). We find…

We observe enhanced second-harmonic generation in monolayer graphene in the presence of an ultra-strong terahertz field pulse with a peak amplitude of 250 kV/cm. This is a strongly nonperturbative regime of light-matter interaction in which…

Graphene and few-layer graphene at high bias expose a wealth of phenomena due to the high temperatures reached. With in-situ transmission electron microscopy (TEM) we observe directly how the current modifies the structure, and vice versa.…

A density-matrix formalism within the length gauge is developed for the purpose of calculating the nonlinear response of intrinsic bilayer graphene at terahertz frequencies. Employing a tight-binding model, we find that interplay between…

In this work, we present numerical results for the second and third order conductivities of the plain graphene and gapped graphene monolayers associated with the second and third harmonic generation, the optical rectification and the…

Although massless Dirac fermions in graphene constitute a centrosymmetric medium for in-plane excitations, their second-order nonlinear optical response is nonzero if the effects of spatial dispersion are taken into account. Here we present…

A new type of the graphene-based three-port circulator is suggested and analysed. The cross-section of the component presents a three-layer structure consisting of a layer of silicon, of silica and of graphene. In-plane figure resembles a…

An efficient route to synthesize macroscopic amounts of graphene is highly desired and a bulk characterization of such samples, in terms of the number of layers, is equally important. We present a Raman spectroscopy-based method to…

The reflectivity of low energy electrons from graphene on copper substrates is studied both experimentally and theoretically. Well-known oscillations in the reflectivity of electrons with energies 0 - 8 eV above the vacuum level are…