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Related papers: Triplet excitations in graphene-based systems

200 papers

The feature-rich electronic excitations of monolayer germanene lie in the significant spin-orbital coupling and the buckled structure. The collective and single- particle excitations are diversified by the magnitude and direction of…

Computational Physics · Physics 2016-04-26 Po-Hsin Shih , Yu-Huang Chiu , Jhao-Ying Wu , Feng-Lin Shyu , Ming-Fa Lin

We argue that the unscreened Coulomb interaction in graphene provides a positive, universal, and logarithmic correction to scaling of zero-temperature conductivity with frequency. The combined effect of the disorder due to wrinkling of the…

Mesoscale and Nanoscale Physics · Physics 2008-01-28 Igor F. Herbut , Vladimir Juricic , Oskar Vafek

We propose that recent transport experiments revealing the existence of an energy gap in graphene nanoribbons may be understood in terms of Coulomb blockade. Electron interactions play a decisive role at the quantum dots which form due to…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 F. Sols , F. Guinea , A. H. Castro Neto

Graphene nanodisk is a graphene derivative with a closed edge. The trigonal zigzag nanodisk with size $N$ has $N$-fold degenerated zero-energy states. We investigate electron-electron interaction effects in the zero-energy sector. We…

Strongly Correlated Electrons · Physics 2008-04-10 Motohiko Ezawa

We theoretically calculate the interaction-induced frictional Coulomb drag resistivity between two graphene monolayers as well as between two graphene bilayers, which are spatially separated by a distance "$d$". We show that the drag…

Mesoscale and Nanoscale Physics · Physics 2011-12-23 E. H. Hwang , Rajdeep Sensarma , S. Das Sarma

We performed tunneling spectroscopy measurements of graphene coupled to niobium/niobium-nitride superconducting electrodes. Due to the proximity effect, the graphene density of states depends on the phase difference between the…

The interaction between electrons and plasmons in trilayer graphene is investigated within the Overhauser approach resulting in the 'plasmaron' quasi-particle. This interaction is cast into a field theoretical problem, nd its effect on the…

Mesoscale and Nanoscale Physics · Physics 2014-01-07 P. M. Krstajić , B. Van Duppen , F. M. Peeters

We apply quantum continuum mechanics to the calculation of the excitation spectrum of a coupled electron-hole bilayer. The theory expresses excitation energies in terms of ground-state intra- and inter-layer pair correlation functions,…

Strongly Correlated Electrons · Physics 2021-10-04 S. De Palo , P. E. Trevisanutto , G. Senatore , G. Vignale

We study the problem of the electron excitation spectrum in the presence of point-like and regularized Coulomb impurities in gapped graphene. To this end, we use the Dirac model and in the point-like case theory of self-adjoint extensions…

Mesoscale and Nanoscale Physics · Physics 2020-08-26 A. I. Breev , R. Ferreira , D. M. Gitman , B. L. Voronov

Recent experiments on twisted bilayer graphene show the urgent need for establishing a low-energy lattice model for the system. We use the constrained random phase approximation to study the interaction parameters of such models taking into…

Strongly Correlated Electrons · Physics 2020-08-05 Tuomas I. Vanhala , Lode Pollet

Coulomb blockade is observed in a graphene nanoribbon device with a top gate. When two pn junctions are formed via the back gate and the local top gate, electrons are confined between the pn junctions which act as the barriers. When no pn…

Mesoscale and Nanoscale Physics · Physics 2009-12-11 Xinglan Liu , Jeroen B. Oostinga , Alberto F. Morpurgo , Lieven M. K. Vandersypen

We examine the 1/N expansion, where N is the number of two-component Dirac fermions, for Coulomb interactions in graphene with a gap of magnitude $\Delta = 2 m$. We find that for $N\alpha\gg1$, where $\alpha$ is graphene's "fine structure…

Mesoscale and Nanoscale Physics · Physics 2022-03-07 Valeri N. Kotov , Bruno Uchoa , A. H. Castro Neto

The electronic energy spectrum of graphene electron subjected to a homogeneous magnetic field in the presence of a charged Coulomb impurity is studied analytically within two-dimensional Dirac-Weyl picture by using variational approach. The…

Mesoscale and Nanoscale Physics · Physics 2010-05-21 B. S. Kandemir , A. Mogulkoc

Due to their unique electron dispersion and lack of a Fermi surface, Coulomb interactions in undoped two-dimensional Dirac systems, such as single, bi- and tri-layer graphene, can be marginal or relevant. Relevant interactions can result in…

Mesoscale and Nanoscale Physics · Physics 2014-02-27 Y. Lee , D. Tran , K. Myhro , J. Velasco , N. Gillgren , C. N. Lau , Y. Barlas , J. M. Poumirol , D. Smirnov , F. Guinea

The polarizability of twisted bilayer graphene, due to the combined effect of electron-hole pairs, plasmons, and acoustic phonons is analyzed. The screened Coulomb interaction allows for the for- mation of Cooper pairs and superconductivity…

Strongly Correlated Electrons · Physics 2021-08-12 Tommaso Cea , Francisco Guinea

We present a theory of electronic properties of gated triangular graphene quantum dots with zigzag edges as a function of size and carrier density. We focus on electronic correlations, spin and geometrical effects using a combination of…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 P. Potasz , A. D. Guclu , A. Wojs , P. Hawrylak

Quantum dots connected to larger systems containing a continuum of states like charge reservoirs allow the theoretical study of many-body effects such as the Coulomb blockade and the Kondo effect. Here, we analyze the nonequilibrium Kondo…

Mesoscale and Nanoscale Physics · Physics 2020-01-31 Levente Máthé , Ioan Grosu

We obtain a novel bound state spectrum of the low energy excitations near the Fermi points of graphene in the presence of a charge impurity. The effects of possible short range interactions induced by the impurity are modelled by suitable…

High Energy Physics - Theory · Physics 2009-11-13 Kumar S. Gupta , Siddhartha Sen

We present a supersymmetric description of the quantum Hall effect (QHE) in graphene. The noninteracting system is supersymmetric separately at the so-called K and K' points of the Brillouin zone corners. Its essential consequence is that…

Mesoscale and Nanoscale Physics · Physics 2007-12-15 Motohiko Ezawa

Single-layer and Bilayer of graphene are new classes of two-dimensional electron systems with unconventional band structures and valley degrees of freedom. The ground states and excitations in the integer and fractional quantum Hall regimes…

Strongly Correlated Electrons · Physics 2015-05-13 Naokazu Shibata , Kentaro Nomura