相关论文: Carrier-envelope phase effects in graphene
We investigate the impact of an induced mass term $\Delta$ on the current density in graphene subjected to a space- and time-dependent periodic potential $U(x,t)$. By solving the Dirac equation and deriving both the quasi-energy spectrum…
We study nonequilibrium carriers (electrons and holes) in an intrinsic graphene at low temperatures under far- and mid-infrared (IR) radiation in a wide range of its intensities. The energy distributions of carriers are calculated using a…
We perform theoretical investigations of laser-induced nonsequential double ionization with few cycle pulses, with particular emphasis on the dependence of the electron-momentum distributions on the carrier-envelope phase. We focus on the…
Certain layered transition metal dichalcogenides (TMDCs), such as 1T-TaS2, show a rich collection of charge density wave (CDW) phases at different temperatures, and their atomic structures and electron conductions have been widely studied.…
When light is absorbed by a semiconductor, photoexcited charge carriers enhance the absorption of far-infrared radiation due to intraband transitions. We observe the opposite behavior in monolayer graphene, a zero-gap semiconductor with…
Two-dimensional carbon, or graphene, is a semi-metal that presents unusual low-energy electronic excitations described in terms of Dirac fermions. We analyze in a self-consistent way the effects of localized (impurities or vacancies) and…
The dynamical approach is applied to ballistic transport in mesoscopic graphene samples of length L and contact potential U. At times shorter than both relevant time scales, the flight time and \hslash/U, the major effect of the electric…
Electro-optical response of a current-carrying monolayer graphene is studied theoretically. Our calculation takes into account full (diagonal and non-diagonal) conductivity tensor obtained from a particle-conserving out-of-equilibrium…
The dynamical conductivity of interacting multiband electronic systems derived in Ref.[1] is shown to be consistent with the general form of the Ward identity. Using the semiphenomenological form of this conductivity formula, we have…
The recent demonstration of saturable absorption and negative optical conductivity in the Terahertz range in graphene has opened up new opportunities for optoelectronic applications based on this and other low dimensional materials.…
The shape of a few-cycle terahertz (THz) laser pulse can be optimized to provide control over conduction band populations in graphene. To demonstrate this control in a theoretical way, a spectral parametrization of the driving pulse using…
Pristine monolayer graphene exhibits very poor screening because the density of states vanishes at the Dirac point. As a result, charge relaxation is controlled by the effects of zero-point motion (rather than by the Coulomb interaction)…
We develop a microscopic theory of an unconventional photogalvanic effect in two-dimensional materials with the Dirac energy spectrum of the carriers of charge under strong driving. As a test bed, we consider a layer of a transition metal…
We describe very fast electron dynamics for a graphene nanoribbon driven by a control electromagnetic field in the terahertz regime. The mobility as a function of bias possesses a large threshold value when entering a nonlinear transport…
Photon-assisted electron transport in ballistic graphene is analyzed using scattering theory. We show that the presence of an ac signal (applied to a gate electrode in a region of the system) has interesting consequences on electron…
The density of electron-hole pairs produced in a graphene sample immersed in a homogeneous time-dependent electrical field is evaluated. Because low energy charge carriers in graphene are described by relativistic quantum mechanics, the…
We study quasi-particle transmission through an $n $-$p$ junction in a graphene irradiated by an electromagnetic field (EF). In the absence of EF the electronic spectrum of undoped graphene is gapless, and one may expect the perfect…
Graphene is a two-dimensional (2D) semimetal with high mobility in charge carriers due to the existence of Dirac points. Silicene is another promising material, with properties analog to graphene. Many silicon (Si) based electronic devices…
Dirac-electronic tunneling and nonlinear transport properties with both finite and zero energy bandgap are investigated for graphene with a tilted potential barrier under a bias. For validation, results from a finite-difference based…
The calculated electron mobility for a graphene nanoribbon as a function of applied electric field has been found to have a large threshold field for entering a nonlinear transport regime. This field depends on the lattice temperature,…