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Related papers: Dielectric function, screening, and plasmons in 2D…

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Numerical and closed-form analytic expressions for plasmon dispersion relations and rates of dissipation are first obtained at finite-temperatures for free-standing gapped graphene. These closed-system results are generalized to an open…

Mesoscale and Nanoscale Physics · Physics 2016-01-20 Andrii Iurov , Godfrey Gumbs , Danhong Huang , V. M. Silkin

We calculate the plasmon dispersion relation for Coulomb coupled metallic armchair graphene nanoribbons and doped monolayer graphene. The crossing of the plasmon curves, which occurs for uncoupled 1D and 2D systems, is split by the…

Mesoscale and Nanoscale Physics · Physics 2017-09-27 S. M. Badalyan , A. A. Shylau , A. P. Jauho

Kohn anomalies in three-dimensional metallic crystals are dips in the phonon dispersion that are caused by abrupt changes in the screening of the ion-cores by the surrounding electron-gas. These anomalies are also present at the…

Mesoscale and Nanoscale Physics · Physics 2013-11-19 F. Forster , A. Molina-Sanchez , S. Engels , A. Epping , K. Watanabe , T. Taniguchi , L. Wirtz , C. Stampfer

The Coulomb excitations of charge density oscillation are calculated for a double-layer heterostructure. Specifically, we consider two-dimensional (2D) layers of silicene and graphene on a substrate. From the obtained surface response…

Mesoscale and Nanoscale Physics · Physics 2022-11-30 Dipendra Dahal , Godfrey Gumbs , Andrii Iurov , Chin-Sen Ting

We investigate the dispersion relations of TE resonances in different graphene-dielectric structures. Previous work has shown that when a graphene layer is brought into contact with a dielectric material, a gap can appear in its electric…

Optics · Physics 2016-05-04 Julia F. M. Werra , Francesco Intravaia , Kurt Busch

We calculate the dynamic polarizability under the random phase approximation for the dice lattice. This two-dimensional system gives rise to massless Dirac fermions with pseudospin-1 in the low-energy quantum excitation spectrum, providing…

Mesoscale and Nanoscale Physics · Physics 2016-05-04 John D. Malcolm , Elisabeth J. Nicol

The response of Dirac fermions to a Coulomb potential is predicted to differ significantly from the behavior of non-relativistic electrons seen in traditional atomic and impurity systems. Surprisingly, many key theoretical predictions for…

Mesoscale and Nanoscale Physics · Physics 2013-05-02 Yang Wang , Victor W. Brar , Andrey V. Shytov , Qiong Wu , William Regan , Hsin-Zon Tsai , Alex Zettl , Leonid S. Levitov , Michael F. Crommie

In this paper, we calculated the dielectric function, the loss function, the magnetoplasmon dispersion relation and the temperature-induced transitions for graphene in a uniform perpendicular magnetic field B. The calculations were…

Mesoscale and Nanoscale Physics · Physics 2014-04-14 Jhao-Ying Wu , Szu-Chao Chen , Oleksiy Roslyak , Godfrey Gumbs , Ming-Fa Lin

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

The {\pi}-plasmon dispersion in graphene was scrutinized by momentum(q)-resolved electron energy-loss spectroscopy with an improved q resolution and found to display the square root of q dispersion characteristic of the collective…

Strongly Correlated Electrons · Physics 2015-06-23 S. C. Liou , C. -S. Shie , C. H. Chen , R. Breitwieser , W. W. Pai , G. Y. Guo , M. -W. Chu

We theoretically consider the effect of plasmon collective modes on the frequency-dependent conductivity of graphene in the presence of the random static potential of charged impurities. We develop an equation of motion approach suitable…

Mesoscale and Nanoscale Physics · Physics 2013-08-09 K. Kechedzhi , S. Das Sarma

The ability to effectively guide electromagnetic radiation below the diffraction limit is of the utmost importance in the prospect of all-optical plasmonic circuitry. Here, we propose an alternative solution to conventional metal-based…

Mesoscale and Nanoscale Physics · Physics 2016-11-28 P. A. D. Gonçalves , E. J. C. Dias , Sanshui Xiao , M. I. Vasilevskiy , N. Asger Mortensen , N. M. R. Peres

Collective modes of doped two-dimensional crystalline materials, namely graphene, MoS$_2$ and phosphorene, both monolayer and bilayer structures, are explored using the density functional theory simulations together with the random phase…

Mesoscale and Nanoscale Physics · Physics 2018-02-06 Zahra Torbatian , Reza Asgari

Self-consistent field theory is used to obtain the non-local plasmon dispersion relation of monolayer graphene which is Coulomb-coupled to a thick conductor. We calculate numerically the undamped plasmon excitation spectrum for arbitrary…

Materials Science · Physics 2014-12-24 Godfrey Gumbs , Andrii Iurov , N. J. M. Horing

We develop a dielectric matrix and analyze plasmon dispersion in strongly coupled charged-particle bilayers in the quantum domain. The formulation is based on the classical quasi-localized charge approximation (QLCA) and extends the QLCA…

Other Condensed Matter · Physics 2009-11-10 Kenneth I. Golden , Hania Mahassen , Gabor J. Kalman , Gaetano Senatore , F. Rapisarda

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

Electrons in two-dimensional graphene sheets behave as interacting chiral Dirac fermions and have unique screening properties due to their symmetry and reduced dimensionality. By using a combination of scanning tunneling spectroscopy…

We develop a microscopic large-$N$ theory of electron-electron interaction corrections to multi-legged Feynman diagrams describing second- and third-order nonlinear response functions. Our theory, which reduces to the well-known random…

Materials Science · Physics 2017-01-25 Habib Rostami , Mikhail I. Katsnelson , Marco Polini

Plasmons in low-dimensional systems respresent an important tool for coupling energy into nanostructures and the localization of energy on the scale of only a few nanometers. Contrary to ordinary surface plasmons of metallic bulk materials,…

Mesoscale and Nanoscale Physics · Physics 2017-01-19 H. Pfnür , C. Tegenkamp , L. Vattuone

The dispersion relation of surface plasmon polaritons in graphene that includes optical losses is often obtained for complex wave vectors while the frequencies are assumed to be real. This approach, however, is not suitable for describing…

Mesoscale and Nanoscale Physics · Physics 2021-09-01 Zeeshan Ahmad , Egor A. Muljarov , Sang Soon Oh