Related papers: Negative terahertz conductivity in disordered grap…
The lateral interdigital array of the graphene microribbons (GMRs) on the h-BN substrate connected by narrow graphene nanoribbon (GNR) bridges serves as an efficient detector of terahertz (THz) radiation. The detection is enabled by the…
The linear electrodynamic properties of graphene -- the frequency-dependent conductivity, the transmission spectra and collective excitations -- are briefly outlined. The non-linear frequency multiplication effects in graphene are studied,…
Terahertz (THz) anisotropic absorption in graphene could be significantly modified upon applying a static magnetic field on its ultra-fast 2D Dirac electrons. In general, by deriving the generalized Fresnel coefficients for monolayer…
In recent years, the telecommunications field has experienced an unparalleled proliferation of wireless data traffic. Innovative solutions are imperative to circumvent the inherent limitations of the current technology, in particular in…
The optical conductivity of freely suspended graphene was examined under non-equilibrium conditions using femtosecond pump-probe spectroscopy. We observed a conductivity transient that varied strongly with the electronic temperature,…
Graphene bilayer systems are known to exhibit a band gap when the layer symmetry is broken, by applying a perpendicular electric field. The resulting band structure resembles that of a conventional semiconductor with a parabolic dispersion.…
Double layer graphene is a gapless semiconductor which develops a finite gap when the layers are placed at different electrostatic potentials. We study, within the tight-biding approximation, the electronic properties of the gaped graphene…
By taking into account the full four band energy spectrum, we calculate the transmission probability and conductance of electrons across symmetric and asymmetric double potential barrier with a confined interlayer potential difference in…
Twisted bilayer graphene (TBG) hosts nearly flat bands with narrow bandwidths of a few meV at certain {\em magic} twist angles. Here we show that in twisted gapped Dirac material bilayers, or massive twisted bilayer graphenes (MTBG),…
The in-plane DC conductivity of twisted bilayer graphene (TBLG) is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding (TB) approach the transport…
We present an electrically switchable graphene terahertz (THz) modulator with a tunable-by-design optical bandwidth and we exploit it to compensate the cavity dispersion of a quantum cascade laser (QCL). Electrostatic gating is achieved by…
Using the microscopic nonlinear quantum theory of interaction of strong coherent electromagnetic radiation with a gapped bilayer graphene is developed for high harmonic generation at low-energy photon excitation-induced Lifshitz…
Electron transport in bilayer graphene placed under a perpendicular electric field is revealed experimentally. Steep increase of the resistance is observed under high electric field; however, the resistance does not diverge even at low…
Epitaxial graphene mesas and ribbons are investigated using terahertz (THz) nearfield microscopy to probe surface plasmon excitation and THz transmission properties on the sub-wavelength scale. The THz near-field images show variation of…
We numerically calculate the optical conductivity of twisted graphene bilayers within the continuum model. To obtain the imaginary part, we employ the regularized Kramers-Kronig relation allowing us to discuss arbitrary twist angles,…
Phase modulation plays a crucial role in various terahertz applications, including biomedical imaging, high-rate communication, and radar detection. Existing terahertz phase shifters typically rely on tuning the resonant effect of…
Graphene is a new material showing high promise in optoelectronics, photonics, and energy-harvesting applications. However, the underlying physical mechanism of optoelectronic response has not been established. Here, we report on the…
We study the effect of an in-plane magnetic field on the non-interacting dispersion of twisted bilayer graphene. Our analysis is rooted in the chirally symmetric continuum model, whose zero-field band structure hosts exactly flat bands and…
The existence of strong trigonal warping around the K point for the low energy electronic states in multilayer (N$\geq$2) graphene films and graphite is well established. It is responsible for phenomena such as Lifshitz transitions and…
We investigate the contribution of the low-energy electronic excitations towards the Raman spectrum of bilayer graphene for the incoming photon energy Omega >> 1eV. Starting with the four-band tight-binding model, we derive an effective…