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Related papers: Vacuum Polarization and Screening of Supercritical…

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We study the Dirac equation for quasiparticles in gapped graphene with two oppositely charged impurities by using the technique of linear combination of atomic orbitals and variational Galerkin--Kantorovich method. We show that for…

Strongly Correlated Electrons · Physics 2015-09-03 E. V. Gorbar , V. P. Gusynin , O. O. Sobol

It is shown that a ``vacuum polarization'' induced by Coulomb potential in graphene leads to a strong suppression of electric charges even for undoped case (no charge carriers). A standard linear response theory is therefore not applicable…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. I. Katsnelson

We address the problem of an unscreened Coulomb charge in graphene, and calculate the local density of states and displaced charge as a function of energy and distance from the impurity. This is done non-perturbatively in two different…

Strongly Correlated Electrons · Physics 2007-10-17 Vitor M. Pereira , Johan Nilsson , A. H. Castro Neto

We calculate exactly the vacuum polarization charge density in the field of a subcritical Coulomb impurity, $Z|e|/r$, in graphene. Our analysis is based on the exact electron Green's function, obtained by using the operator method, and…

Mesoscale and Nanoscale Physics · Physics 2008-02-25 Ivan S. Terekhov , Alexander I. Milstein , Valeri N. Kotov , Oleg P. Sushkov

We review the theoretical and experimental results connected with the electron states in two-dimensional Dirac systems paying a special attention to the atomic collapse in graphene. Two-electron bound states of a Coulomb impurity are…

Strongly Correlated Electrons · Physics 2018-06-15 E. V. Gorbar , V. P. Gusynin , O. O. Sobol

We reveal a new type of supercritical behavior in gapped graphene with two oppositely charged impurities by studying the two-dimensional Dirac equation for quasiparticles with the Coulomb potential regularized at small distances accounting…

Strongly Correlated Electrons · Physics 2015-12-14 E. V. Gorbar , V. P. Gusynin , O. O. Sobol

We study the distribution of vacuum polarization charge induced by a Coulomb impurity in massive graphene. By analytically computing the polarization function, we show that the charge density is distributed in space in a non-trivial…

Mesoscale and Nanoscale Physics · Physics 2008-08-22 Valeri N. Kotov , Vitor M. Pereira , Bruno Uchoa

Since the experimental realization of graphene1, extensive theoretical work has focused on short-range disorder2-5, ''ripples''6, 7, or charged impurities2, 3, 8-13 to explain the conductivity as a function of carrier density…

Other Condensed Matter · Physics 2009-11-13 J. H. Chen , C. Jang , M. S. Fuhrer , E. D. Williams , M. Ishigami

We calculate the average single particle density of states in graphene with disorder due to impurity potentials. For unscreened short-ranged impurities, we use the non-self-consistent and self-consistent Born and $T$-matrix approximations…

Mesoscale and Nanoscale Physics · Physics 2008-10-18 Ben Yu-Kuang Hu , E. H. Hwang , S. Das Sarma

Introducing quasiparticle anisotropy in graphene via uniaxial strain has a profound effect on the polarization charge density induced by external impurities, both Coulomb and short-range. In particular, the charge distribution induced by a…

Mesoscale and Nanoscale Physics · Physics 2023-12-21 Mohamed M. Elsayed , Sang Wook Kim , Juan M. Vanegas , Valeri N. Kotov

We analyze the scattering sector of the Hamiltonians for both gapless and gapped graphene in the presence of a charge impurity using the 2D Dirac equation, which is applicable in the long wavelength limit. We show that for certain range of…

Mesoscale and Nanoscale Physics · Physics 2011-04-07 Kumar S. Gupta , Andjelo Samsarov , Siddhartha Sen

We theoretically investigate the impurity levels and exchange interaction between magnetic impurities in graphene driven by an off-resonant circularly polarized light field. Our analysis captures the non-perturbative effects resulting from…

Mesoscale and Nanoscale Physics · Physics 2022-08-29 Modi Ke , Wang-Kong Tse

Graphene is an attractive material for microelectronics applications, given such favourable electrical characteristics as high mobility, high operating frequency, and good stability. If graphene is to be implemented in electronic devices on…

Materials Science · Physics 2019-06-14 B. C. Worley , S. Kim , T. J. Ha , S. Park , R. Haws , P. Rossky , D. Akinwande , A. Dodabalapur

We study massless Dirac fermions in a supercritical Coulomb potential with the emphasis on that its low-energy physics is universal and parametrized by a single quantity per supercritical angular momentum channel. This low-energy parameter…

Mesoscale and Nanoscale Physics · Physics 2014-10-16 Yusuke Nishida

Analytical solutions of the Coulomb impurity problem of graphene in the absence of a magnetic field show that when the dimensionless strength of the Coulomb potential $g$ reaches a critical value the solutions become supercritical with…

Mesoscale and Nanoscale Physics · Physics 2014-05-23 S. C. Kim , S. -R. Eric Yang

We consider the problem of screening of an electrically charged impurity in a clean graphene sheet. When electron-electron interactions are neglected, the screening charge has a sign opposite to that of the impurity, and is localized near…

Strongly Correlated Electrons · Physics 2007-11-29 Rudro R. Biswas , Subir Sachdev , Dam T. Son

We demonstrate how potential impurities are a very powerful tool for determining the pairing symmetry in graphene proximity-coupled to a spin-singlet superconductor. All d-wave states are characterized by subgap resonances, with spatial…

Superconductivity · Physics 2018-06-20 Oladunjoye A. Awoga , Annica M. Black-Schaffer

We revisit the problem of bound states in graphene under the influence of point electric monopole and dipole impurity potentials extended to the case in which the membrane of this material is uniformly and uniaxially strained, which leads…

Mesoscale and Nanoscale Physics · Physics 2020-08-20 J. C. Pérez-Pedraza , E. Díaz-Bautista , A. Raya , D. Valenzuela

Defects in graphene are of crucial importance for its electronic and magnetic properties. Here impurity effects on the electronic structure of surrounding carbon atoms are considered and the distribution of the local densities of states…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 T. O. Wehling , A. V. Balatsky , M. I. Katsnelson , A. I. Lichtenstein , K. Scharnberg , R. Wiesendanger

The ground-state and the transport properties of graphene subject to the potential of in-plane charged impurities are studied. The screening of the impurity potential is shown to be nonlinear, producing a fractal structure of electron and…

Mesoscale and Nanoscale Physics · Physics 2009-12-02 M. M. Fogler
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