English
Related papers

Related papers: Why Dirac points in graphene are where they are?

200 papers

We present a detailed theoretical study of bilayer-graphene's electronic properties in the presence of electric and magnetic fields. Using group-theoretical methods, we derive an invariant expansion of the Hamiltonian for electron states…

Mesoscale and Nanoscale Physics · Physics 2015-07-01 R. Winkler , U. Zülicke

The effective theory for bilayer graphene (BLG), subject to parallel/in-plane magnetic fields, is derived. With a sizable magnetic field the trigonal warping becomes irrelevant, and one ends up with two Dirac points in the vicinity of each…

Mesoscale and Nanoscale Physics · Physics 2014-01-08 Bitan Roy , Kun Yang

Topological aspects of graphene are reviewed focusing on the massless Dirac fermions with/without magnetic field. Doubled Dirac cones of graphene are topologically protected by the chiral symmetry. The quantum Hall effect of the graphene is…

Mesoscale and Nanoscale Physics · Physics 2012-04-30 Yasuhiro Hatsugai

We present the results of the first principle calculations of the energy bands in graphene and their symmetry classification. The valence bands and four lowest conduction bands are classified according to their symmetry at the points…

Mesoscale and Nanoscale Physics · Physics 2013-05-30 E. Kogan , V. U. Nazarov

We investigate the fine structure in the energy spectrum of bilayer graphene in the presence of various stacking defaults, such as a translational or rotational mismatch. This fine structure consists of four Dirac points that move away from…

Mesoscale and Nanoscale Physics · Physics 2013-10-22 R. de Gail , M. O. Goerbig , G. Montambaux

The emergence of flat bands in twisted bilayer graphene at the magic angle can be understood in terms of a vanishing Fermi velocity of the Dirac cone. This is associated with van Hove singularities approaching the Fermi energy and becoming…

Strongly Correlated Electrons · Physics 2023-06-05 A. S. Shankar , D. O. Oriekhov , Andrew K. Mitchell , L. Fritz

We consider the electronic structure of a slightly twisted graphene bilayer and show the coexistence of van Hove singularities (VHSs) and superlattice Dirac points in a continuum approximation. The graphene-on-graphene moir\'e pattern gives…

Mesoscale and Nanoscale Physics · Physics 2013-04-19 Zhao-Dong Chu , Wen-Yu He , Lin He

We demonstrate theoretically that the topology of energy bands and Fermi surface in bilayer graphene undergoes a very sensitive transition when extremely tiny lateral interlayer shift occurs in arbitrary directions. The phenomenon…

Mesoscale and Nanoscale Physics · Physics 2011-10-17 Young-Woo Son , Seon-Myeong Choi , Yoon Pyo Hong , Sungjong Woo , Seung-Hoon Jhi

We investigate the spectrum and the dispersion relation of the Schr\"odinger operator with point scatterers on a triangular lattice and a honeycomb lattice. We prove that the low-level dispersion bands have conic singularities near Dirac…

Mathematical Physics · Physics 2016-09-13 Minjae Lee

The low energy excitations of graphene can be described by a massless Dirac equation in two spacial dimensions. Curved graphene is proposed to be described by coupling the Dirac equation to the corresponding curved space. This covariant…

Strongly Correlated Electrons · Physics 2009-11-13 Maria A. H. Vozmediano , Fernando de Juan , Alberto Cortijo

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of…

Materials Science · Physics 2014-11-20 D. S. L. Abergel , V. Apalkov , J. Berashevich , K. Ziegler , Tapash Chakraborty

Using the tight-binding model, we report a gap opening in the energy spectrum of the twisted bilayer graphene under the application of pressure, that can be further amplified by the presence of a perpendicular bias voltage. The valley edges…

Mesoscale and Nanoscale Physics · Physics 2025-03-27 V. G. M. Duarte , D. R. da Costa , N. M. R. Peres , L. K. Teles , A. J. Chaves

Layered kagome-lattice 3d transition metals are emerging as an exciting platform to explore the frustrated lattice geometry and quantum topology. However, the typical kagome electronic bands, characterized by sets of the Dirac-like band…

We theoretically reexamine nearly uniform electron models with weak crystalline potentials. In particular, we theorize the modulation of the plane-wave branches at linear regions where multiple Bragg planes intersect. Any such linear…

Materials Science · Physics 2024-07-30 Ryosuke Akashi

Application of secondary quantized self-consistent Dirac -- Hartree -- Fock approach to consider electronic properties of monolayer graphene with accounting of spin-polarized states allows to coherently explain experimental results on…

Mesoscale and Nanoscale Physics · Physics 2013-09-10 H. V. Grushevskaya , G. G. Krylov

We compute the dynamical polarizability of graphene beyond the usual Dirac cone approximation, integrating over the full Brillouin zone. We find deviations at $\hbar\omega=2t$ ($t$ the hopping parameter) which amount to a logarithmic…

Mesoscale and Nanoscale Physics · Physics 2010-02-05 T. Stauber , J. Schliemann , N. M. R. Peres

We find a systematic reappearance of massive Dirac features at the edges of consecutive minibands formed at magnetic fields B_{p/q}= p\phi_0/(qS) providing rational magnetic flux through a unit cell of the moire superlattice created by a…

Mesoscale and Nanoscale Physics · Physics 2014-02-10 Xi Chen , J. R. Wallbank , A. A. Patel , M. Mucha-Kruczynski , E. McCann , V. I. Fal'ko

\textit{Holey Graphene} (HG) is a widely used graphene material for the synthesis of high-purity and highly crystalline materials. In this work, we explore the electronic properties of a periodic distribution of lattice holes, demonstrating…

Mesoscale and Nanoscale Physics · Physics 2024-04-09 Abdiel de Jesús Espinosa-Champo , Gerardo G. Naumis

We study the orbital effect of a strong magnetic field parallel to the layers on the energy spectrum of the Bernal-stacked graphene bilayer and multilayers, including graphite. We consider the minimal model with the electron tunneling…

Mesoscale and Nanoscale Physics · Physics 2010-11-15 Sergey S. Pershoguba , Victor M. Yakovenko

Since the discovery of magic-angle twisted bilayer graphene (TBG), flat bands in Dirac materials have become a prominent platform for realizing strong correlation effects in electronic systems. Here we show that the symmetry group…

Strongly Correlated Electrons · Physics 2023-12-20 Yarden Sheffer , Raquel Queiroz , Ady Stern