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Related papers: Low-energy optical sum-rule in moir\'e graphene

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We analyze the competing effects of moderate to strong Coulomb electron-electron interactions and weak quenched disorder in graphene. Using a one-loop renormalization group calculation controlled within the large-N approximation, we…

Disordered Systems and Neural Networks · Physics 2009-11-13 Matthew S. Foster , Igor L. Aleiner

We study the renormalization of the effective mass and trigonal warping of bilayer graphene by the electron-electron interaction. One consequence of such a renormalization in the low-energy bands of a bilayer crystal consists of a small…

Mesoscale and Nanoscale Physics · Physics 2009-03-16 Csaba Toke , Vladimir I. Fal'ko

We study the electronic properties of twisted bilayers graphene in the tight-binding approximation. The interlayer hopping amplitude is modeled by a function, which depends not only on the distance between two carbon atoms, but also on the…

Mesoscale and Nanoscale Physics · Physics 2015-08-12 A. O. Sboychakov , A. L. Rakhmanov , A. V. Rozhkov , Franco Nori

Motivated by recent experimental findings on the low-energy spectrum of Kekul\'e-patterned graphene, the optoelectronic signatures of graphene superlattices with a spatial modulation that triples the size of the unit cell and folds the…

Mesoscale and Nanoscale Physics · Physics 2021-09-22 Saúl A. Herrera , Gerardo G. Naumis

The electrostatic confinement of massless charge carriers is hampered by Klein tunneling. Circumventing this problem in graphene mainly relies on carving out nanostructures or applying electric displacement fields to open a band gap in…

We derive the renormalization group equations describing all the short-range interactions in bilayer graphene allowed by symmetry and the long range Coulomb interaction. For certain range of parameters, we predict the first order phase…

Strongly Correlated Electrons · Physics 2013-12-19 Y. Lemonik , I. L. Aleiner , C. Toke , V. I. Fal'ko

Recent fluorescence spectroscopy experiments on single wall carbon nanotubes reveal substantial deviations of observed absorption and emission energies from predictions of noninteracting models of the electronic structure. Nonetheless, the…

Materials Science · Physics 2009-11-10 C. L. Kane , E. J. Mele

We calculate the single-particle spectral function for doped bilayer graphene in the low energy limit, described by two parabolic bands with zero band gap and long range Coulomb interaction. Calculations are done using thermal Green's…

Mesoscale and Nanoscale Physics · Physics 2014-04-18 Andro Sabashvili , Stellan Östlund , Mats Granath

Twisted bilayer graphene (TBG) exhibits a wide range of intriguing physical properties, such as superconductivity, ferromagnetism, and superlubricity. Depending on the twist angle, periodic moir\'e superlattices form in twisted bilayer…

Mesoscale and Nanoscale Physics · Physics 2022-06-07 Vahid Morovati , Zhiming Xue , Kenneth M. Liechti , Rui Huang

In graphene moir\'e superlattices, electronic interactions between layers are mostly hidden as band structures get crowded because of folding, making their interpretation cumbersome. Here, the evolution of the electronic band structure as a…

Mesoscale and Nanoscale Physics · Physics 2021-09-01 Francisco Sanchez-Ochoa , Andres Botello-Mendez , Cecilia Noguez

We investigate the gap in the single-electron spectrum of twisted bilayer graphene. In a perfect infinite lattice of a twisted bilayer, the gap varies exponentially in response to weak changes of the twist angle. Such a large sensitivity…

Mesoscale and Nanoscale Physics · Physics 2017-01-17 A. V. Rozhkov , A. O. Sboychakov , A. L. Rakhmanov , Franco Nori

In moir\'{e} systems with twisted bilayer graphene (tBLG), the amplification of Coulomb correlation effects at low twist angles ($\theta$) is a result of nearly flat low-energy electronic bands and divergent density of states (DOS) at van…

We present exact results that give insight into how interactions lead to transport and superconductivity in a flat band where the electrons have no kinetic energy. We obtain bounds for the optical spectral weight for flat band…

Superconductivity · Physics 2021-08-25 Nishchhal Verma , Tamaghna Hazra , Mohit Randeria

Coulomb interaction is of central importance in localized energy levels (bound states) or electronic flat bands and could result in many exotic quantum phases, such as magnetic, superconducting, and topological phases in graphene…

Mesoscale and Nanoscale Physics · Physics 2020-08-25 Zhong-Qiu Fu , Ke-Ke Bai , Ya-Ning Ren , Jiao-Jiao Zhou , Lin He

In gapped bilayer graphene, similarly to conventional semiconductors, Coulomb impurities (such as nitrogen donors) may determine the activation energy of its conductivity and provide low temperature hopping conductivity. However, in spite…

Mesoscale and Nanoscale Physics · Physics 2024-05-21 E. V. Gorbar , V. P. Gusynin , D. O. Oriekhov , B. I. Shklovskii

In strong magnetic fields, massless electrons in graphene populate relativistic Landau levels with the square-root dependence of each level energy on its number and magnetic field. Interaction-induced deviations from this single-particle…

Mesoscale and Nanoscale Physics · Physics 2017-03-07 A. A. Sokolik , A. D. Zabolotskiy , Yu. E. Lozovik

Spin-orbit coupling (SOC) and electron-electron interaction can mutually influence each other and give rise to a plethora of intriguing phenomena in condensed matter systems. In pristine bilayer graphene, which has weak SOC, intrinsic…

We analyze charging effects in graphene quantum dots. Using a simple model, we show that, when the Fermi level is far from the neutrality point, charging effects lead to a shift in the electrostatic potential and the dot shows standard…

Mesoscale and Nanoscale Physics · Physics 2008-02-06 B. Wunsch , T. Stauber , F. Guinea

Bilayer graphene in a magnetic field supports eight zero-energy Landau levels, which, as a tunable band gap develops, split into two nearly-degenerate quartets separated by the band gap. A close look is made into the properties of such an…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 K. Shizuya

The impact of the electron-electron Coulomb interaction on the optical conductivity of graphene has led to a controversy that calls into question the universality of collisionless transport in this and other Dirac materials. Using a lattice…

Strongly Correlated Electrons · Physics 2016-07-06 Julia M. Link , Peter P. Orth , Daniel E. Sheehy , Jörg Schmalian