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Related papers: Intense-pulse dynamics of massless Dirac electrons

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Electronic properties of materials are commonly described by quasiparticles that behave as non-relativistic electrons with a finite mass and obey the Schroedinger equation. Here we report a condensed matter system where electron transport…

Mesoscale and Nanoscale Physics · Physics 2011-05-05 K. S. Novoselov , A. K. Geim , S. V. Morozov , D. Jiang , M. I. Katsnelson , I. V. Grigorieva , S. V. Dubonos , A. A. Firsov

The optical properties of graphene are made unique by the linear band structure and the vanishing density of states at the Dirac point. It has been proposed that even in the absence of a semiconducting bandgap, a relaxation bottleneck at…

Many of graphene's unique electronic properties emerge from its Dirac-like electronic energy spectrum. Similarly, it is expected that a nanophotonic system featuring Dirac dispersion will open a path to a number of important research…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 J. Bravo-Abad , J. D. Joannopoulos , M. Soljacic

We have calculated the dynamical polarization, plasmons and damping rates in semi-Dirac bands (SDB's) with zero band gap and half-linear, half-parabolic low-energy spectrum. The obtained plasmon dispersions are strongly anisotropic and…

Mesoscale and Nanoscale Physics · Physics 2023-12-27 Gabrielle Ross-Harvey , Andrii Iurov , Liubov Zhemchuzhna , Godfrey Gumbs , Danhong Huang

A remarkable manifestation of the quantum character of electrons in matter is offered by graphene, a single atomic layer of graphite. Unlike conventional solids where electrons are described with the Schrodinger equation, electronic…

Mesoscale and Nanoscale Physics · Physics 2008-09-16 Z. Q. Li , E. A. Henriksen , Z. Jiang , Z. Hao , M. C. Martin , P. Kim , H. L. Stormer , D. N. Basov

We study quasiparticle dynamics in graphene exposed to a linearly-polarized electromagnetic wave of very large intensity. Low-energy transport in such system can be described by an effective time-independent Hamiltonian, characterized by…

Mesoscale and Nanoscale Physics · Physics 2014-02-18 S. V. Syzranov , Ya. I. Rodionov , K. I. Kugel , F. Nori

Two-dimensional lattices of coupled micropillars etched in a planar semiconductor microcavity offer a workbench to engineer the band structure of polaritons. We report experimental studies of honeycomb lattices where the polariton…

In this paper we study the excitation spectrum of graphene in a strong magnetic field, beyond the Dirac cone approximation. The dynamical polarizability is obtained using a full $\pi$-band tight-binding model where the effect of the…

Mesoscale and Nanoscale Physics · Physics 2012-09-03 Shengjun Yuan , Rafael Roldán , Mikhail I. Katsnelson

We study the interaction of electrons in graphene with the quantized electromagnetic field in the presence of an applied uniform electric field using the Dirac model of graphene. Electronic states are represented by exact solutions of the…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 N. Yokomizo

The quasi-2D electrons in graphene behave as massless fermions obeying a Dirac-Weyl equation in the low-energy regime near the two Fermi points. The stability of spin-polarized phases (SPP) in graphene is considered. The exchange energy is…

Strongly Correlated Electrons · Physics 2007-05-23 M. W. C. Dharma-wardana

We have investigated the absorption spectrum of multilayer graphene in high magnetic fields. The low energy part of the spectrum of electrons in graphene is well described by the relativistic Dirac equation with a linear dispersion…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 P. Plochocka , C. Faugeras , M. Orlita , M. L. Sadowski , G. Martinez , M. Potemski , M. O. Goerbig , J. -N. Fuchs , C. Berger , W. A. de Heer

The Dirac-like quasiparticles in honeycomb graphene lattice are taken to possess a non-zero effective mass. The charge carriers involve to interact with a femtosecond strong laser pulse. Due to the scattering time of electrons in graphene…

Mesoscale and Nanoscale Physics · Physics 2017-01-31 Z. Ahmadi , H. Goudarzi , A. Jafari

We theoretically study the Dirac fermion dynamics in a graphene monolayer in the presence of an applied ultrafast laser pulse. The pulse has the duration of a few femtoseconds and the amplitude of ~ 0.1 - 0.5 $\mathrm{V/\AA}$. The waveform…

Mesoscale and Nanoscale Physics · Physics 2019-09-12 S. Azar Oliaei Motlagh , Vadym Apalkov , Mark I. Stockman

Ultrafast optical pump-probe spectroscopy measurement on monolayer graphene observes significant optical nonlinearities. We show that strongly photoexcited graphene monolayers with 35 fs pulses quasi-instantaneously build up a broadband,…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Junhua Zhang , Joerg Schmalian , Tianqi Li , Jigang Wang

We generalise the usual framework of Dirac-Bloch equations, used to compute the nonlinear optical response of 2D materials excited by spatially uniform optical pulses, to the case of structured light pulses. We derive the general form of…

Optics · Physics 2022-07-07 Yaraslau Tamashevich , Marco Ornigotti

Electrons moving in graphene behave as massless Dirac fermions, and they exhibit fascinating low-frequency electrical transport phenomena. Their dynamic response, however, is little known at frequencies above one terahertz (THz). Such…

We discuss the properties of 1D stationary pulses of light in atomic ensemble with electromagnetically induced transparency in the limit of tight spatial confinement. When the size of the wavepacket becomes comparable or smaller than the…

Quantum Physics · Physics 2009-11-13 J. Otterbach , R. G. Unanyan , M. Fleischhauer

The unusual transport properties of graphene are the direct consequence of a peculiar bandstructure near the Dirac point. We determine the shape of the pi bands and their characteristic splitting, and the transition from a pure 2D to…

Materials Science · Physics 2007-05-23 Taisuke Ohta , Aaron Bostwick , J. L. McChesney , Thomas Seyller , Karsten Horn , Eli Rotenberg

Plasmon opens up the possibility to efficiently couple light and matter at sub-wavelength scales. In general, the plasmon frequency is dependent of carrier density. This dependency, however, renders fundamentally a weak plasmon intensity at…

Materials Science · Physics 2019-11-20 Jianfeng Wang , Xuelei Sui , Shiwu Gao , Wenhui Duan , Feng Liu , Bing Huang

The outstanding electronic properties of relativistic-like fermions have been extensively studied in solid state systems with isotropic linear dispersions such as graphene. Here, we show that 2D and 3D Dirac-Weyl (DW) materials exhibiting…

Mesoscale and Nanoscale Physics · Physics 2018-06-13 Viet Hung Nguyen , Jean-Christophe Charlier