Related papers: Plasmon modes in bilayer-monolayer graphene hetero…
In this work we study the behavior of the optical phonon modes in bilayer graphene devices by applying top gate voltage, using Raman scattering. We observe the splitting of the Raman G band as we tune the Fermi level of the sample, which is…
The interplay between substrate interactions and electron-phonon coupling in two-dimensional (2D) materials presents a significant challenge in understanding and controlling their electronic properties. Here, we present a comparative study…
We derive a material-realistic real-space many-body Hamiltonian for twisted bilayer graphene from first principles, including both single-particle hopping terms for $p_z$ electrons and long-range Coulomb interactions. By disentangling low-…
Holey graphene (HG) is a novel two-dimensional (2D) material that has attracted considerable attention due to its remarkable electrical, thermal, and mechanical properties. The recent discovery of flat bands in HG has garnered significant…
Coupling of plasmons in graphene at terahert (THz) frequencies with surface plasmons in a heavily-doped substrate is studied theoretically. We reveal that a huge scattering rate may completely damp out the plasmons, so that proper choices…
A density-matrix formalism within the length gauge is developed to calculate the nonlinear response of both doped and undoped biased bilayer graphene (BBLG) at terahertz frequencies. Employing a tight-binding model, we derive an effective…
A method for the substantial reduction of propagation loss of surface plasmons was proposed and experimentally demonstrated. The method is based on the fact that the propagation loss of the surface plasmons depends significantly on the…
We present numerical and analytical results for the optical and acoustic plasmon collective modes of coupled massless-Dirac two-dimensional electron systems. Our results apply to topological insulator (TI) thin films and to two graphene…
Pragmatic ways of including lifetime broadening of collective modes in the electron liquid are critically compared. Special focus lies on the impact of the damping parameter onto the dispersion. It is quantitatively exemplified for the…
The optical response of graphene micro-structures, such as micro-ribbons and disks, is dominated by the localized plasmon resonance in the far infrared (IR) spectral range. An ensemble of such structures is usually involved and the effect…
We report a nano-infrared (IR) imaging study of trilayer graphene (TLG) with both ABA (Bernal) and ABC (rhombohedral) stacking orders using the scattering-type scanning near-field optical microscope (s-SNOM). With s-SNOM operating in the…
Electrons on the liquid helium surface form an extremely clean two dimensional system where different plasmon-excitations can coexist. Under a magnetic field time reversal symmetry is broken and all the bulk magneto-plasmons become gaped at…
We investigate the dispersion relations of TE resonances in different graphene-dielectric structures. Previous work has shown that when a graphene layer is brought into contact with a dielectric material, a gap can appear in its electric…
We have analytically studied plasmons in an electron system comprised of two spatially separated layers -- an infinite two-dimensional electron system (2DES) and a 2D strip. Our analysis reveals the existence of plasmon modes that are…
We investigate theoretically the energy transfer phenomenon in a double-layer graphene (DLG) system in which two layers are coupled due to the Coulomb interlayer interaction without appreciable interlayer tunneling. We use the balance…
We analytically obtain the dispersion relations for transverse-electric (TE) and transverse-magnetic (TM) surface plasmon-polaritons in a nonlinear two-dimensional (2D) conducting material lying between two Kerr-type dielectric media. To…
We have investigated surface shear waves at 22 MHz in a 0.5-micron-thick polymer film on SiO2/Si substrate at low temperatures using suspended and non-suspended graphene as detectors. By tracking ultrasound modes detected by oscillations of…
We study nonlinear modes in one-dimensional arrays of doped graphene nanodisks with Kerr-type nonlinear response in the presence of an external electric field. We present the theoretical model describing the evolution of the disks'…
We demonstrate that single-layer graphene in the presence of a metal gate displays a gapless collective (plasmon) mode that has a linear dispersion at long wavelengths. We calculate exactly the acoustic-plasmon group velocity at the level…
By using an asymptotic analysis and numerical simulations, we derive and investigate a system of homogenized Maxwell's equations for conducting material sheets that are periodically arranged and embedded in a heterogeneous and anisotropic…