English
Related papers

Related papers: Topological effects, index theorem and supersymmet…

200 papers

We study the problem of a single Dirac fermion in a quantizing orbital magnetic field, when the chemical potential is at the Dirac point. This can be realized on the surface of a topological insulator, such as Bi2Se3, tuned to neutrality.…

Strongly Correlated Electrons · Physics 2010-03-05 Ying Ran , Hong Yao , Ashvin Vishwanath

While the quantum Hall effect in graphene has been regarded as a realization of the anomaly associated with the massless Dirac particle carrying half the usual topological integer, this is hidden due to the doubling of the Dirac cones. In…

Mesoscale and Nanoscale Physics · Physics 2014-08-01 Haruki Watanabe , Yasuhiro Hatsugai , Hideo Aoki

A hybrid structure combining the advantages of topological insulator (TI), dielectric ferromagnet (FM), and graphene is investigated to realize the electrically controlled correlation between electronic and magnetic subsystems for…

Mesoscale and Nanoscale Physics · Physics 2014-07-11 Xiaopeng Duan , Yuriy G. Semenov , Ki Wook Kim

We study topological phases of time-reversal invariant singlet superconductors in three spatial dimensions. In these particle-hole symmetric systems the topological phases are characterized by an even-numbered winding number $\nu$. At a…

Mesoscale and Nanoscale Physics · Physics 2009-05-15 Andreas P. Schnyder , Shinsei Ryu , Andreas W. W. Ludwig

The gap equation for Dirac quasiparticles in monolayer graphene in constant magnetic and pseudomagnetic fields, where the latter is due to strain, is studied in a low-energy effective model with contact interactions. Analyzing solutions of…

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

Starting from the graphene lattice tight-binding Hamiltonian with an on-site U and long-range Coulomb repulsion, we derive an interacting continuum Dirac theory governing the low-energy behavior of graphene in an applied magnetic field.…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Jason Alicea , Matthew P. A. Fisher

We analyze the energy spectrum of graphene in the presence of spin-orbit coupling and a unidirectionally periodic Zeeman field, focusing on the stability and location of Dirac points it may support. It is found that the Dirac points at the…

Mesoscale and Nanoscale Physics · Physics 2016-08-24 Luis Brey , A. R. Carvalho , H. A. Fertig

We present a supersymmetric description of the quantum Hall effect (QHE) in graphene. The noninteracting system is supersymmetric separately at the so-called K and K' points of the Brillouin zone corners. Its essential consequence is that…

Mesoscale and Nanoscale Physics · Physics 2007-12-15 Motohiko Ezawa

The long standing controversy concerning the effect of electron - electron interaction on the electrical conductivity of an ideal graphene sheet is settled. Performing the calculation directly in the tight binding approach without the usual…

Strongly Correlated Electrons · Physics 2015-06-11 B. Rosenstein , M. Lewkowicz , T. Maniv

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

The different physical properties of multilayered graphene or graphite relative to single layer graphene result from the Dirac spins symmetry in graphene and the Pauli spin symmetry in graphite. The Dirac symmetry in multilayers of graphene…

Materials Science · Physics 2011-10-28 Reginald B. Little , Glenn J. Gex , Muhammad Ansari , James W. Mitchell

We present exact analytical solutions for the zero-energy modes of two-dimensional massless Dirac fermions fully confined within a smooth one-dimensional potential V(x)= - {\alpha}/cosh({\beta}x), which provides a good fit for potential…

Mesoscale and Nanoscale Physics · Physics 2010-07-01 R. R. Hartmann , N. J. Robinson , M. E. Portnoi

Three-dimensional topological insulators are characterized by insulating bulk state and metallic surface state involving Dirac fermions that behave as massless relativistic particles. These Dirac fermions are responsible for achieving a…

We study the influence of a localized Gaussian deformation on massless Dirac fermions confined to a two-dimensional curved surface. Both in-plane and out-of-plane displacements are considered within the framework of elasticity theory. These…

Mesoscale and Nanoscale Physics · Physics 2026-02-09 Samuel B. B. Almeida , J. E. G. Silva , C. A. S. Almeida

Flat bands are of significant interest due to their potential for energy confinement and their ability to enable strongly correlated physics. Incorporating topology into flatband systems further enhances flatband mode robustness against…

Optics · Physics 2025-04-01 Yongsheng Liang , Jingyan Zhan , Shiqi Xia , Daohong Song , Zhigang Chen

At low energy, electrons in doped graphene sheets behave like massless Dirac fermions with a Fermi velocity which does not depend on carrier density. Here we show that modulating a two-dimensional electron gas with a long-wavelength…

Mesoscale and Nanoscale Physics · Physics 2009-06-29 M. Gibertini , A. Singha , V. Pellegrini , M. Polini , G. Vignale , A. Pinczuk , L. N. Pfeiffer , K. W. West

We show that the continuum limit of moir\'e graphene is described by a $(2+1)$-dimensional field theory of Dirac fermions coupled to two classical vector fields: a periodic gauge and spin field. We further show that the existence of a flat…

Mesoscale and Nanoscale Physics · Physics 2024-09-17 Alireza Parhizkar , Victor Galitski

An exact mapping of the tight-binding Hamiltonian for a graphene's nanoribbon under any armchair uniaxial strain into an effective one-dimensional system is presented. As an application, for a periodic modulation we have found a gap opening…

Mesoscale and Nanoscale Physics · Physics 2015-04-27 Pedro Roman-Taboada , Gerardo G. Naumis

This work analyzes monolayer graphene in external electromagnetic fields, which is described by the Dirac equation with minimal coupling. Supersymmetric quantum mechanics allows building new Dirac equations with modified magnetic fields.…

Mesoscale and Nanoscale Physics · Physics 2022-09-07 Miguel Castillo-Celeita , Alonso Contreras-Astorga , David J. Fernández C

We study the energy spectrum and electronic properties of graphene in a periodic magnetic field of zero average with a symmetry of triangular lattice. The periodic field leads to formation of a set of minibands separated by gaps, which can…

Materials Science · Physics 2015-05-30 M. Taillefumier , V. K. Dugaev , B. Canals , C. Lacroix , P. Bruno