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Related papers: Dynamical centrosymmetry breaking in graphene

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We observe enhanced second-harmonic generation in monolayer graphene in the presence of an ultra-strong terahertz field pulse with a peak amplitude of 250 kV/cm. This is a strongly nonperturbative regime of light-matter interaction in which…

This work analyzes monolayer graphene in external electromagnetic fields, which is described by the Dirac equation with minimal coupling. Supersymmetric quantum mechanics allows building new Dirac equations with modified magnetic fields.…

Mesoscale and Nanoscale Physics · Physics 2022-09-07 Miguel Castillo-Celeita , Alonso Contreras-Astorga , David J. Fernández C

Tuning interactions between Dirac states in graphene has attracted enormous interest because it can modify the electronic spectrum of the two-dimensional material, enhance electron correlations, and give rise to novel condensed-matter…

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

Extended defects in graphene, such as linear edges, break the translational invariance and can also have an impact on the symmetries specific to massless Dirac-like quasiparticles in this material. The paper examines the consequences of a…

Mesoscale and Nanoscale Physics · Physics 2009-05-25 Grigory Tkachov , Martina Hentschel

We investigate the effect of phenomenological relaxation parameters on the third order optical nonlinearity of doped graphene by perturbatively solving the semiconductor Bloch equation around the Dirac points. An analytic expression for the…

Materials Science · Physics 2015-12-24 J. L. Cheng , N. Vermeulen , J. E. Sipe

We investigate generation of new Dirac cones in graphene under double-periodic and quasiperiodic superlattice potentials. We first show that double-periodic potentials generate the Dirac cones sporadically, following the Diophantine…

Mesoscale and Nanoscale Physics · Physics 2015-04-08 Masayuki Tashima , Naomichi Hatano

A study of the formation of excitons as a problem of two Dirac particles in a gapped graphene layer and in two gapped graphene layers separated by a dielectric is presented. In the low energy limit the separation of the center-of-mass and…

Mesoscale and Nanoscale Physics · Physics 2013-07-30 O. L. Berman , R. Ya. Kezerashvili , K. Ziegler

We report measurements of the cyclotron mass in graphene for carrier concentrations n varying over three orders of magnitude. In contrast to the single-particle picture, the real spectrum of graphene is profoundly nonlinear so that the…

The dispersion relation for the collective plasma excitations of optically dressed Dirac electrons in single and double graphene layers is calculated in the random-phase approximation. The presence of circularly polarized light gives rise…

Materials Science · Physics 2015-05-27 Oleksiy Roslyak , Godfrey Gumbs , Danhong Huang

In this paper, we investigate the two competing effects of strains and magnetic fields in single-layer graphene to explore its impact on various phenomena of quantum field theory, such as induced charge density, magnetic catalysis, symmetry…

High Energy Physics - Theory · Physics 2021-01-05 J. A. Sánchez-Monroy , C. J. Quimbay

We show how the two-dimensional Dirac oscillator model can describe some properties of electrons in graphene. This model explains the origin of the left-handed chirality observed for charge carriers in monolayer and bilayer graphene. The…

Mesoscale and Nanoscale Physics · Physics 2013-11-21 C. Quimbay , P. Strange

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…

We present analytical expressions for the eigenstates and eigenvalues of electrons confined in a graphene monolayer in the presence of a disclination. The calculations are performed in the continuum limit approximation in the vicinity of…

Mesoscale and Nanoscale Physics · Physics 2017-11-03 Debabrata Sinha , Bertrand Berche

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 investigate the electronic structure of a twisted multilayer graphene system forming a moir\'e pattern. We consider small twist angles separating the graphene sheets and develop a low-energy theory to describe the coupling of Dirac Bloch…

Mesoscale and Nanoscale Physics · Physics 2019-07-17 Christophe Mora , Nicolas Regnault , B. Andrei Bernevig

Chiral symmetry, fundamental in the physics of graphene, guarantees the existence of topologically stable doubled Dirac cones and anomalous behaviors of the zero-energy Landau level in magnetic fields. The crucial role is inherited in the…

Mesoscale and Nanoscale Physics · Physics 2013-11-13 Y. Hatsugai , T. Morimoto , T. Kawarabayashi , Y. Hamamoto , H. Aoki

For centrosymmetric materials such as monolayer graphene, no optical second harmonic generation (SHG) is generally expected because it is forbidden under the electric-dipole approximation. Yet we observed a strong, doping induced SHG from…

Mesoscale and Nanoscale Physics · Physics 2019-02-12 Yu Zhang , Di Huang , Yuwei Shan , Tao Jiang , Zhihong Zhang , Kaihui Liu , Lei Shi , Jinluo Cheng , John E. Sipe , Wei-Tao Liu , Shiwei Wu

Graphene has received a great deal of attention and this has more recently extended to boron nitride sheets (BNS) with a similar structure. Both have hexagonal lattices and it is only the alternation of atoms in boron nitride, which changes…

Chemical Physics · Physics 2016-02-23 A. F. Jalbout , T. H. Seligman

We study the generation of harmonics from graphene under the influence of an artificial magnetic field, generated via bending of a graphene flake. We show how the Landau level structure induced by the pseudomagnetic field breaks the…

Mesoscale and Nanoscale Physics · Physics 2024-06-12 Marco Ornigotti , Luca Ornigotti , Fabio Biancalana