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Pseudorelativistic Dirac quasiparticles have emerged in a plethora of artificial graphene systems that mimic the underlying honeycomb symmetry of graphene. However, it is notoriously difficult to manipulate their properties without…

Two-dimensional (2D) Dirac states and Dirac points with linear dispersion are the hallmark of graphene, topological insulators, semimetals, and superconductors. Lowering a symmetry by the ferroelectric polarization opens the gap in Dirac…

Mesoscale and Nanoscale Physics · Physics 2025-07-03 Konstantin S. Denisov , Yuntian Liu , Igor Žutić

We show that diffraction of electromagnetic radiation (in particular of a visible light) can disappear in propagation through materials with periodically in space modulated refraction index, i.e. photonic crystals. In this way the light…

Optics · Physics 2009-11-11 K. Staliunas , R. Herrero

Dirac phenomenological coupled channel analyses are performed using an optical potential model for the high-lying excited vibrational states at 800 MeV unpolarized proton inelastic scatterings from $^{22}$Ne nucleus. Lorentz-covariant…

Nuclear Theory · Physics 2016-01-20 Sugie Shim , Moon-Won Kim

Partial solutions of the Dirac equation describing an electron motion in electromagnetic crystals created by plane waves with linear and circular polarizations are treated. It is shown that the electromagnetic crystal formed by circularly…

Quantum Physics · Physics 2014-10-22 G. N. Borzdov

We demonstrate that symmetry breaking opens a new degree of freedom to tailor the energy-momentum dispersion in photonic crystals. Using a general theoretical framework in two illustrative practical structures, we show that breaking…

Kinematic diffraction is well suited for a mathematical approach via measures, which has substantially been developed since the discovery of quasicrystals. The need for further insight emerged from the question of which distributions of…

Materials Science · Physics 2019-07-17 Michael Baake , Uwe Grimm

The Dirac cone underlies many unique electronic properties of graphene and topological insulators, and its band structure--two conical bands touching at a single point--has also been realized for photons in waveguide arrays, atoms in…

In this article: a) a method is developed for calculating volumetric diagrams of elastic scattering of microparticles (in particular, electrons and photons) on single-layer and multi-layer statistically uneven surfaces; b) the diffraction…

General Physics · Physics 2021-04-06 Mikhail Batanov-Gaukhman

Using scanning tunneling spectroscopy we have measured the response of Dirac electrons in a magnetic field to the presence of a well-defined smoothly varying 1D periodic potential. We find that the lower index Landau level energies reliably…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Yoshinori Okada , Wenwen Zhou , Chetan. Dhital , D. Walkup , Ying Ran , Z. Wang , Stephen D. Wilson , V. Madhavan

We study the electronic band structures of massless Dirac fermions in symmetrical graphene superlattice with cells of three regions. Using the transfer matrix method, we explicitly determine the dispersion relation in terms of different…

Mesoscale and Nanoscale Physics · Physics 2018-07-04 Abdellatif Kamal , El Bouâzzaoui Choubabi , Ahmed Jellal

Dirac points lie at the heart of many fascinating phenomena in condensed matter physics, from massless electrons in graphene to the emergence of conducting edge states in topological insulators [1, 2]. At a Dirac point, two energy bands…

Quantum Gases · Physics 2013-06-26 Leticia Tarruell , Daniel Greif , Thomas Uehlinger , Gregor Jotzu , Tilman Esslinger

We proceed with the construction of normalizable Dirac wave packets for treating chiral oscillations in the presence of an external magnetic field. Both chirality and helicity quantum numbers correspond to variables of fundamental…

High Energy Physics - Theory · Physics 2009-11-10 Alex E. Bernardini

Structure and properties of two-dimensional spiral textures in helical ferromagnets have been studied. In these magnetic mediums have been predicted new types of periodical structures - spiral lattices.

Strongly Correlated Electrons · Physics 2013-01-03 A. B. Borisov , F. N. Rybakov

Direct current in clean semiconductors and metals was recently shown to obey the laws of hydrodynamics in a broad range of temperatures and sample dimensions. However, the determination of frequency window for hydrodynamic phenomena remains…

Mesoscale and Nanoscale Physics · Physics 2019-12-04 Dmitry Svintsov

We are looking at a Dirac electron in the electromagnetic field of a plane monochrome polarized X-ray. It will be attempted to link the terms of a certain (joint) asymptotic expansion of the Heisenberg propagations of momentum- and…

General Physics · Physics 2018-01-08 H. O. Cordes

A single Dirac cone on the surface is the hallmark of three-dimensional (3D) topological insulators, where the double degeneracy at the Dirac point is protected by time-reversal symmetry and the spin-splitting away from the point is…

Mesoscale and Nanoscale Physics · Physics 2016-01-05 Ling Lu , Chen Fang , Liang Fu , Steven G. Johnson , John D. Joannopoulos , Marin Soljačić

Dispersive time-decay estimates are proved for a one-parameter family of one-dimensional Dirac Hamiltonians with dislocations; these are operators which interpolate between two phase-shifted massive Dirac Hamiltonians at $x=+\infty$ and…

Analysis of PDEs · Mathematics 2024-07-19 Joseph Kraisler , Amir Sagiv , Michael I. Weinstein

Graphene-based superlattice (SL) formed by a periodic gap modulation is studied theoretically using a Dirac-type Hamiltonian. Analyzing the dispersion relation we have found that new Dirac points arise in the electronic spectrum under…

Mesoscale and Nanoscale Physics · Physics 2015-06-11 G. M. Maksimova , E. S. Azarova , A. V. Telezhnikov , V. A. Burdov

In this paper, we study the massive Dirac equation with the presence of the Morse potential in polar coordinate. The Dirac Hamiltonian is written as two second-order differential equations in terms of two spinor wavefunctions. Since the…

Quantum Physics · Physics 2021-04-27 Z. Zali , Alireza Amani , J. Sadeghi , B. Pourhassan