Related papers: Transient stimulated emission from multi-split-gat…
Room temperature Terahertz stimulated emission and population inversion in optically pumped graphene is reported. We experimentally observe fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in an…
The luminescence caused by the interband transitions of hot carriers in graphene is considered theoretically. The dependencies of emission in mid- and near-IR spectral regions versus energy and concentration of hot carriers are analyzed;…
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.…
We utilize an organic polymer buffer layer between graphene and conventional gate dielectrics in top-gated graphene transistors. Unlike other insulators, this dielectric stack does not significantly degrade carrier mobility, allowing for…
Diffusion and drift of a graphene flake on a graphite surface are analyzed. A potential energy relief of the graphene flake is computed using ab initio and empirical calculations. Based on the analysis of this relief, different mechanisms…
Graphene is a 2-dimensional material with high carrier mobility and thermal conductivity, suitable for high-speed electronics. Conduction and valence bands touch at the Dirac point. The absorptivity of single-layer graphene is 2.3%, nearly…
We have performed scanning gate microscopy (SGM) on graphene field effect transistors (GFET), using a biased metallic nanowire coated with a dielectric layer as a contact mode tip and local top gate. Electrical transport through graphene at…
We study transmission in a system consisting of a curved graphene surface as an arc (ripple) of circle connected to two flat graphene sheets on the left and right sides. We introduce a mass term in the curved part and study the effect of a…
An energy gap can be opened in the electronic spectrum of graphene by lifting its sublattice symmetry. In bilayers, it is possible to open gaps as large as 0.2 eV. However, these gaps rarely lead to a highly insulating state expected for…
We present a microscopic explanation of the controversially discussed transient negative differential transmission observed in degenerate optical pump-probe measurements in graphene. Our approach is based on the density matrix formalism…
Growth of graphene on monolayer transition-metal dichalcogenides presents opening on band gap and giant spin-orbit coupling which paves the way to achieve a useful hybrid structure for electronics and spintronics applications. Increase of…
We measure the temperature distribution in a biased single-layer graphene transistor using Raman scattering microscopy of the 2D-phonon band. Peak operating temperatures of 1050 K are reached in the middle of the graphene sheet at 210 KW…
A gain-assisted plasmonic waveguide with two detuned resonators is investigated in the plasmon-induced transparency window. Phase map is employed to study power transmittance and group delay for varying gain coefficients and frequency…
We demonstrate a tunneling and rectification behavior in bilayer graphene. A stepped dielectric top gate creates a spatially modulated electric field, which opens the band gap in the graphene and produces an insulating region at the p-n…
We report results of experimental investigation of the low-frequency noise in the top-gate graphene transistors. The back-gate graphene devices were modified via addition of the top gate separated by 20 nm of HfO2 from the single-layer…
Graphene is considered to be a promising candidate for future nano-electronics due to its exceptional electronic properties. Unfortunately, the graphene field-effect-transistors (FETs) cannot be turned off effectively due to the absence of…
In this paper we propose and discuss coherent terahertz sources based on charge density wave (plasmon) amplification in two dimensional graphene. The coupling of the plasmons to interband electron-hole transitions in population inverted…
The generation of highly-confined plasmons through far-field optical illumination appears to be impractical for technological applications due to their large energy-momentum mismatch with external light. Electrical generation of plasmons…
Using ultrafast pump-probe reflectivity with 3.1 eV pump and coherent white light probe (1.1 to 2.6 eV), we show that graphene on gold nanostructures exhibits a strong coupling to the plasmonic resonances of the ordered lattice hole array,…
Graphene plasmons have recently attracted a great deal of attention because of their tunability, long lifetime, and high degree of field confinement in the vertical direction. Nearby metal gates have been shown to modify the graphene…