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Related papers: Triplet excitations in graphene-based systems

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We find exact analytic expressions for the energies and wavefunctions of the charged and neutral excitations above the exact ground states (at rational filling per unit cell) of projected Coulomb Hamiltonians in twisted bilayer graphene.…

Strongly Correlated Electrons · Physics 2022-04-29 B. Andrei Bernevig , Biao Lian , Aditya Cowsik , Fang Xie , Nicolas Regnault , Zhi-Da Song

Generation of high harmonics in a monolayer graphene initiated by strong coherent radiation field, taking into account electron-electron Coulomb interaction is investigated. A microscopic theory describing the nonlinear optical response of…

Mesoscale and Nanoscale Physics · Physics 2018-04-04 H. K. Avetissian , G. F. Mkrtchian

Exciton instability in graphene bilayer systems is studied in the case of a short-ranged Coulomb interaction and a finite voltage difference between the layers. Self-consistent exciton gap equations are derived and solved numerically and…

Strongly Correlated Electrons · Physics 2008-07-02 Raoul Dillenschneider , Jung Hoon Han

Elementary electronic excitations, which are due to the Coulomb-field scatterings, present the diverse phenomena in 3D, 2D, 1D-nanotube electron gases, graphene and carbon nanotubes. The critical mechanisms cover the dimension-dependent…

Mesoscale and Nanoscale Physics · Physics 2020-04-20 Cheng-Hsueh Yang , Chiun-Yan Lin , Chih-Wei Chiu , Chang-Ting Liu , Ming-Fa Lin

We present magneto-Raman scattering studies of electronic inter Landau level excitations in quasi-neutral graphene samples with different strengths of Coulomb interaction. The band velocity associated with these excitations is found to…

In a magnetic field two-dimensional (2d) electron systems host, with quenched kinetic energy, a variety of many-body correlation phenomena, such as interaction-driven new states and associated collective excitations over them. In a magnetic…

Mesoscale and Nanoscale Physics · Physics 2017-06-20 K. Shizuya

We give an update of the situation concerning the effect of electron-electron interactions on the physics of a neutral graphene system at low energies. We revise old renormalization group results and the use of 1/N expansion to address…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 Maria A. H. Vozmediano , Francisco Guinea

We show that free electrons can efficiently excite plasmons in doped graphene with probabilities of order one per electron. More precisely, we predict multiple excitations of a single confined plasmon mode in graphene nanostructures. These…

Mesoscale and Nanoscale Physics · Physics 2014-03-20 F. Javier Garcia de Abajo

We study effects of a repulsive Coulomb interaction on the spectral gap in monolayer and bilayer graphene in the vicinity of the charge neutrality point by employing the functional renormalization-group technique. In both cases Coulomb…

Strongly Correlated Electrons · Physics 2011-04-01 Andreas Sinner , Klaus Ziegler

We have investigated the Coulomb screening properties and plasmon spectrum in a bilayer graphene under a perpendicular electric bias. The bias voltage applied between the two graphene layers opens a gap in the single particle energy…

Mesoscale and Nanoscale Physics · Physics 2010-02-04 Xue-Feng Wang , Tapash Chakraborty

We argue, for a wide class of systems including graphene, that in the low temperature, high density, large separation and strong screening limits the drag resistivity behaves as d^{-4}, where d is the separation between the two layers. The…

Mesoscale and Nanoscale Physics · Physics 2015-03-20 B Amorim , N M R Peres

We use a tight-binding model and the random-phase approximation to study the Coulomb excitations in simple-hexagonal-stacking multilayer graphene and discuss the field effects. The calculation results include the energy bands, the response…

Materials Science · Physics 2015-06-19 Ming-Fa Lin , Ying-Chih Chuang , Jhao-Ying Wu

We theoretically investigate the effects of Coulomb interaction, at the level of unscreened Hartree-Fock approximation, on third harmonic generation of undoped graphene in an equation of motion framework. The unperturbed electronic states…

Mesoscale and Nanoscale Physics · Physics 2020-01-01 J. L. Cheng , J. E. Sipe , Chunlei Guo

Recently, plasmons in graphene have been observed experimentally using scattering scanning near-field optical microscopy. In this paper, we develop a simplified analytical approach to describe the behavior in triangular samples. Replacing…

Mesoscale and Nanoscale Physics · Physics 2013-09-10 A. S. Rodin , Z. Fei , A. S. McLeod , M. Wagner , A. H. Castro Neto , M. M. Fogler , D. N. Basov

We calculate theoretically the Coulomb drag resistivity for two graphene monolayers spatially separated by a distance "$d$". We show that the frictional drag induced by inter-layer electron-electron interaction goes asymptotically as…

Mesoscale and Nanoscale Physics · Physics 2012-01-04 E. H. Hwang , S. Das Sarma

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 study electronic properties of graphene with finite concentration of vacancies or other resonant scatterers by a straightforward lattice Quantum Monte Carlo calculations. Taking into account realistic long-range Coulomb interaction we…

Strongly Correlated Electrons · Physics 2015-06-24 M. V. Ulybyshev , M. I. Katsnelson

The significant electron-electron interactions that characterize the {\pi}-electrons of graphene nanoribbons (GNRs) necessitate going beyond one-electron tight-binding description. Existing theories of electron-electron interactions in GNRs…

Strongly Correlated Electrons · Physics 2016-07-27 V. M. L. Durga Prasad Goli , Suryoday Prodhan , Sumit Mazumdar , S. Ramasesha

We consider graphene in a strong perpendicular magnetic field at zero temperature with an integral number of filled Landau levels and study the dispersion of single particle-hole excitations. We first analyze the two-body problem of a…

Mesoscale and Nanoscale Physics · Physics 2007-09-13 A. Iyengar , Jianhui Wang , H. A. Fertig , L. Brey

We present a quantum analysis of the massless excitations in graphene with a charge impurity. When the effective charge exceeds a certain critical value, the spectrum is quantized and is unbounded from below. The corresponding eigenstates…

Mesoscale and Nanoscale Physics · Physics 2009-02-10 Kumar S. Gupta , Siddhartha Sen