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Related papers: Dynamical centrosymmetry breaking in graphene

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Dirac energy-dispersions are responsible of the extraordinary transport properties of graphene. This motivated the quest for engineering such energy dispersions also in photonics, where they have been predicted to lead to many exciting…

Mesoscale and Nanoscale Physics · Physics 2023-12-05 Erik P. Navarro-Barón , Herbert Vinck-Posada , Alejandro González-Tudela

We have investigated electron band structure of epitaxially grown graphene on an SiC(0001) substrate using angle-resolved photoemission spectroscopy. In single-layer graphene, abnormal high spectral intensity is observed at the Dirac energy…

Materials Science · Physics 2016-04-26 Jinwoong Hwang , Choongyu Hwang

We theoretically demonstrate that a system formed by two coupled graphene sheets enables a negative damping regime wherein graphene plasmons are pumped by a DC current. This effect is triggered by electrons drifting through one of the…

Mesoscale and Nanoscale Physics · Physics 2017-10-04 Tiago A. Morgado , Mário G. Silveirinha

Two-dimensional (2D) Dirac-like electron gases have attracted tremendous research interest ever since the discovery of free-standing graphene. The linear energy dispersion and non-trivial Berry phase play the pivotal role in the remarkable…

The nodal and effectively relativistic dispersion featuring in a range of novel materials including two- dimensional graphene and three-dimensional Dirac and Weyl semimetals has attracted enormous interest during the past decade. Here, by…

Strongly Correlated Electrons · Physics 2018-04-11 Johan Carlström , Emil J. Bergholtz

Graphene's low-energy electronic excitations obey a 2+1 dimensional Dirac Hamiltonian. After extending this Hamiltonian to include interactions with a quantized electromagnetic field, we calculate the amplitude associated with the simplest,…

Mesoscale and Nanoscale Physics · Physics 2014-11-20 Matthew Mecklenburg , Jason Woo , B. C. Regan

Ab initio density functional theory (DFT) simulations were used to investigate an influence of electric field, parallel to single and multilayer graphene on its electron dispersion relations close to K point. It was shown that for both…

Materials Science · Physics 2016-11-09 Stanisław Krukowski , Jakub Sołtys , Jolanta Borysiuk , Jacek Piechota

Graphene/h-BN has emerged as a model van der Waals heterostructure, and the band structure engineering by the superlattice potential has led to various novel quantum phenomena including the self-similar Hofstadter butterfly states. Although…

We study the electronic states of graphene in piecewise constant potentials using the continuum Dirac equation appropriate at low energies, and a transfer matrix method. For superlattice potentials, we identify patterns of induced Dirac…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 D. P. Arovas , L. Brey , H. A. Fertig , Eun-Ah Kim , K. Ziegler

We explore the gapped graphene structure in the two-dimensional plane in the presence of the Rosen-Morse potential and an external uniform magnetic field. In order to describe the corresponding structure, we consider the propagation of…

Mesoscale and Nanoscale Physics · Physics 2024-09-04 A. Kalani , Alireza Amani , M. A. Ramzanpour

The different physical properties of multilayered graphene or graphite relative to single layer graphene result from the Dirac spins symmetry in graphene and the Pauli spin symmetry in graphite. The Dirac symmetry in multilayers of graphene…

Materials Science · Physics 2011-10-28 Reginald B. Little , Glenn J. Gex , Muhammad Ansari , James W. Mitchell

The zero gap electronic bands in the monolayer graphene are shown to be unstable relative to the dynamic symmetry violation due to the electron-phonon interaction.

Mesoscale and Nanoscale Physics · Physics 2009-10-20 Sergey A. Ktitorov , Xiaoxing Chen

The quantum Hall states of graphene have a filled Dirac sea of Landau levels. The short ranged SU(4) symmetry breaking interactions can induce a staggered polarization of the sea of Dirac-Landau levels. We study this effect in the extended…

Mesoscale and Nanoscale Physics · Physics 2007-07-09 Vinu Lukose , R. Shankar

We reveal that optical saturation of the low-energy states takes place in graphene for arbitrarily weak electromagnetic fields. This effect originates from the diverging field-induced interband coupling at the Dirac point. Using…

Mesoscale and Nanoscale Physics · Physics 2024-01-02 Behrooz Semnani , Roland Jago , Safieddin Safavi-Naeini , Amir Hamed Majedi , Ermin Malic , Philippe Tassin

In the present work, we investigate how structural defects in graphene can change its transport properties. In particular, we show that breaking of the sublattice symmetry in a graphene monolayer overcomes the Klein effect, leading to…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 C. Popovici , O. Oliveira , W. de Paula , T. Frederico

Existence and stability of Dirac points in the dispersion relation of operators periodic with respect to the hexagonal lattice is investigated for different sets of additional symmetries. The following symmetries are considered: rotation by…

Mathematical Physics · Physics 2016-12-13 Gregory Berkolaiko , Andrew Comech

We demonstrate that symmetry breaking opens a new degree of freedom to tailor the energy-momentum dispersion in photonic crystals. Using a general theoretical framework in two illustrative practical structures, we show that breaking…

Electron scattering in the monolayer graphene with short-range impurities modelled by the annular well with a band-asymmetric potential has been considered. Band-asymmetry of the potential resulted in the mass (gap) perturbation in the…

Mesoscale and Nanoscale Physics · Physics 2010-02-23 Natalie E. Firsova , Sergey A. Ktitorov

In an ideal graphene sheet charge carriers behave as two-dimensional (2D) Dirac fermions governed by the quantum mechanics of massless relativistic particles. This has been confirmed by the discovery of a half-integer quantum Hall effect in…

Materials Science · Physics 2015-05-13 Yuanbo Zhang , Victor W. Brar , Caglar Girit , Alex Zettl , Michael F. Crommie

Graphene is famous for being a host of 2D Dirac fermions. However, spin-orbit coupling introduces a small gap, so that graphene is formally a quantum spin hall insulator. Here we present symmetry-protected 2D Dirac semimetals, which feature…

Materials Science · Physics 2015-09-23 Steve M. Young , Charles L. Kane