Related papers: Feature-rich plasmon excitations in sliding bilaye…
Strongly correlated phases in twisted bilayer graphene (TBG) typically arise as transitions from a state in which the system behaves as a normal metal. In such metallic regime, electron-electron interactions usually only play a subleading…
We study the effects of long and short-range electron-electron interactions in a graphene bilayer. Using a variational wavefunction technique we show that in the presence of long-range Coulomb interactions the clean bilayer is always…
Recently plasmon excitations in bilayer lattice systems were studied extensively in the weak-coupling regime. Unlike single-layer systems, these bilayers exhibit two distinct modes, $\omega_{\pm}$, which show characteristic dependences upon…
The electronic properties and optical excitations are investigated in the geometry- and field-modulated bilayer graphene systems, respectively, by using the tight-binding model and Kubo formula. The stacking symmetry of bilayer graphene can…
We report on our studies of interacting electrons in bilayer graphene in a magnetic field. We demonstrate that the long range Coulomb interactions between electrons in this material are highly important. We show that in the unbiased bilayer…
We characterise the dynamics of electrons in twisted bilayer graphene by analysing the time-evolution of electron waves in the atomic lattice. We perform simulations based on a kernel polynomial technique using Chebyshev polynomial; this…
We investigate the dispersion relation and damping of plasmon modes in a bilayer-monolayer graphene heterostructure with carrier densities and at zero temperature within the random-phase-approximation taking into account the nonhomogeneity…
Tight-binding model of the AA-stacked bilayer graphene with screened electron-electron interactions has been studied using the Hybrid Monte Carlo simulations on the original double-layer hexagonal lattice. Instantaneous screened Coulomb…
We have theoretically studied the collective response properties of the two-dimensional chiral electron gas in bilayer graphene within the random phase approximation. The cooperation of external controlling factors like perpendicular…
We theoretically study the effects of electron-electron interaction in twisted bilayer graphene in applied transverse dc electric field. When the twist angle is not very small, the electronic spectrum of the bilayer consists of four Dirac…
Twisted graphene bilayers show a complex electronic structure, further modified by interaction effects. The main features can be obtained from effective models, which make use a few phenomenological parameters. We analyze the influence of…
Graphene is a novel two-dimensional material with fascinating electrodynamic properties like the ability to support collective electron oscillations (plasmons) accompanied by tight confinement of electromagnetic fields. Our goal is to…
The effect of screening of the coulomb interaction between two layers of two-dimensional electrons, such as in graphene, by a highly doped semiconducting substrate is investigated. We employ the random-phase approximation to calculate the…
In twisted bilayer graphene, a unified understanding of the mechanisms governing temperature-dependent electronic spectra and thermodynamic properties remains controversial despite extensive theoretical efforts. Here, we present a…
We compute the phase diagram of twisted bilayer graphene near the magic angle where the occurrence of flat bands enhances the effects of electron-electron interactions and thus unleashes strongly-correlated phenomena. Most importantly, we…
Although plasmon modes exist in doped graphene, the limited range of doping achieved by gating restricts the plasmon frequencies to a range that does not include visible and infrared. Here we show, through the use of first-principles…
We theoretically calculate the interaction-induced frictional Coulomb drag resistivity between two graphene monolayers as well as between two graphene bilayers, which are spatially separated by a distance "$d$". We show that the drag…
Spatially separated electron systems remain strongly coupled by electron-electron interactions even when they cannot exchange particles, provided that the layer separation d is comparable to a characteristic distance l between charge…
Plasmon and coupled plasmon-phonon modes in graphene are investigated the-oretically within the diagrammatic self-consistent field theory. It shows that two plasmon modes and four coupled plasmon-phonon modes can be excited via intra-and…
Plasmons in two-dimensional electron systems with nonparabolic bands, such as graphene, feature strong dependence on electron-electron interactions. We use a many-body approach to relate plasmon dispersion at long wavelengths to Landau…