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Related papers: Coulomb center instability in bilayer graphene

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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 investigate the effect of on-site Coulomb repulsion $U$ on the band gap of the electrically gated bilayer graphene by employing coherent potential approximation in the paramagnetic state, based on an ionic two-layer Hubbard model. We…

Strongly Correlated Electrons · Physics 2016-03-17 Jin-Rong Xu , Ze-Yi Song , Hai-Qing Lin , Yu-Zhong Zhang

The strong long-range Coulomb interaction between massless Dirac fermions in graphene can drive a semimetal-insulator transition. We show that this transition is strongly suppressed when the Coulomb interaction is screened by such effects…

Strongly Correlated Electrons · Physics 2015-05-13 Guo-Zhu Liu , Wei Li , Geng Cheng

To obtain an effective many-body model of graphene and related materials from first principles we calculate the partially screened frequency dependent Coulomb interaction. In graphene, the effective on-site (Hubbard) interaction is U_00 =…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 T. O. Wehling , E. Sasioglu , C. Friedrich , A. I. Lichtenstein , M. I. Katsnelson , S. Blügel

Using the self-consistent Hartree-Fock approximation, we study the compressibility instability of the interacting electrons in bilayer graphene. The chemical potential and the compressibility of the electrons can be significantly altered by…

Strongly Correlated Electrons · Physics 2011-01-11 Xin-Zhong Yan , C. S. Ting

The effect of Coulomb interaction in an ensemble of Dirac fermions on the formation of superconducting pairing in monolayer and bilayer doped graphene is studied using the Kohn-Luttinger mechanism disregarding the Van der Waals potential of…

Superconductivity · Physics 2015-01-19 M. Yu. Kagan , V. A. Mitskan , M. M. Korovushkin

We investigate the instabilities of interacting electrons on the honeycomb bilayer by means of the functional renormalization group for a range of interactions up to the third-nearest neighbor. Besides a novel instability toward a gapless…

Strongly Correlated Electrons · Physics 2012-08-20 Michael M. Scherer , Stefan Uebelacker , Carsten Honerkamp

In a recent publication [Phys. Rev. B $\textbf{89}$, 155403 (2014)], the authors investigated the spectrum of a Coulomb impurity in graphene in the presence of magnetic and electric fields using the coupled series expansion approach. In the…

Mesoscale and Nanoscale Physics · Physics 2018-06-06 R. Van Pottelberge , M. Zarenia , F. M. Peeters

When electrons populate a flat band their kinetic energy becomes negligible, forcing them to organize in exotic many-body states to minimize their Coulomb energy. The zeroth Landau level of graphene under magnetic field is a particularly…

The gap generation is studied in suspended clean graphene in the continuum model for quasiparticles with the Coulomb interaction. We solve the gap equation with the dynamical polarization function and show that, comparing to the case of the…

Strongly Correlated Electrons · Physics 2014-11-20 O. V. Gamayun , E. V. Gorbar , V. P. Gusynin

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

Few layers of graphene at small twist-angles have emerged as a fascinating platform for studying the problem of strong interactions in regimes with a nearly quenched single-particle kinetic energy and non-trivial band topology. Starting…

Strongly Correlated Electrons · Physics 2024-11-06 J. F. Mendez-Valderrama , Dan Mao , Debanjan Chowdhury

By applying a self-consistent Hartree-Fock approximation, we show that the mechanism of dynamical symmetry breaking can account for the insulating phase that develops about the charge neutrality point of twisted bilayer graphene around the…

Mesoscale and Nanoscale Physics · Physics 2020-09-02 J. Gonzalez , T. Stauber

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 extend previous analyses of fermions on a honeycomb bilayer lattice via weak-coupling renormalization group (RG) methods with extremely short-range and extremely long-range interactions to the case of finite-range interactions. In…

Strongly Correlated Electrons · Physics 2012-10-04 Robert E. Throckmorton , Oskar Vafek

In this paper, we numerically study a Coulomb impurity problem for interacting Dirac fermions restricted in disordered graphene quantum dots. In the presence of randomly distributed lattice defects and spatial potential fluctuations, the…

Mesoscale and Nanoscale Physics · Physics 2020-11-25 Mustafa Polat , A. D. Güçlü

For bilayer graphene in a magnetic field at the neutral point, we derive and solve a full set of gap equations including all Landau levels and taking into account the dynamically screened Coulomb interaction. There are two types of the…

Mesoscale and Nanoscale Physics · Physics 2012-07-02 E. V. Gorbar , V. P. Gusynin , V. A. Miransky , I. A. Shovkovy

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

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 Coulomb drag in double-layer graphene near the Dirac point. A particular emphasis is put on the case of clean graphene, with transport properties dominated by the electron-electron interaction. Using the quantum kinetic equation…

Mesoscale and Nanoscale Physics · Physics 2013-06-26 M. Schütt , P. M. Ostrovsky , M. Titov , I. V. Gornyi , B. N. Narozhny , A. D. Mirlin