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Related papers: Photonic Dirac Waveguides

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We show that a planar array of bipolar waveguides in graphene can be used to engineer gapped and tilted two-dimensional Dirac cones within the electronic band structure. The presence of these gapped and tilted Dirac cones is demonstrated…

Mesoscale and Nanoscale Physics · Physics 2024-12-02 A. Wild , R. R. Hartmann , E. Mariani , M. E. Portnoi

In Dirac materials, the low energy excitations obey the relativistic Dirac equation. This dependence implies that the electrons are exposed to strong spin-orbit coupling. Hence, real spin conservation is believed to be violated in Dirac…

Mesoscale and Nanoscale Physics · Physics 2019-05-27 Vanessa Werner , Björn Trauzettel , Oleksiy Kashuba

The relativistic semiclassical evolution of the position of an electron in the presence of an external electromagnetic field is studied in terms of a Newton equation that incorporates spin effects directly. This equation emerges from the…

Quantum Physics · Physics 2017-11-13 R. Gutierrez-Jauregui , R. Perez-Pascual , R. Jauregui

Moir\'e heterostructures provide a powerful framework for tailoring electronic band structures via controlled long-range periodic superlattice potentials. Beyond widely studied moir\'e-tailored flat bands, folded band structures can host…

Strongly Correlated Electrons · Physics 2026-04-29 R. Ganser , M. P. T. Masilamani , B. Geldiyev , M. M. Hirschmann , A. Consiglio , J. Schusser , D. Di Sante , M. Ünzelmann , F. Reinert

We study the collective charge-density modes (plasmons) of two-dimensional nonsymmorphic Dirac semimetals, within the random-phase approximation (RPA) in presence of Coulomb interaction. Without loss of generality, we consider a system in a…

Mesoscale and Nanoscale Physics · Physics 2023-02-23 Debasmita Giri , Arijit Kundu

Metasurfaces are sub-wavelength patterned layers for controlling waves in physical systems. In optics, meta-surfaces are created by materials with different dielectric constants and are capable of unconventional functionalities. We develop…

Computational Physics · Physics 2024-08-21 Chen-Di Han , Li-Li Ye , Zin Lin , Vassilios Kovanis , Ying-Cheng Lai

Spin-1 condensed matter systems characterized by the combination of a Dirac-like dispersion and flat bands are ideal for realizing high-temperature electronics and spintronic technologies in the absence of external magnetic field. In this…

Mesoscale and Nanoscale Physics · Physics 2019-07-19 Muhammad Nadeem , Xiaolin Wang

We propose a new concept of two-dimensional (2D) Dirac semiconductor which is characterized by the emergence of fourfold degenerate band crossings near the band edge and provide a generic approach to realize this novel semiconductor in the…

Materials Science · Physics 2022-02-02 Botao Fu , Chao He , Da-Shuai Ma , Zhi-Ming Yu , Yong-Hong Zhao , Yugui Yao

Dirac-electronic tunneling and nonlinear transport properties with both finite and zero energy bandgap are investigated for graphene with a tilted potential barrier under a bias. For validation, results from a finite-difference based…

Mesoscale and Nanoscale Physics · Physics 2020-04-01 Farhana Anwar , Andrii Iurov , Danhong Huang , Godfrey Gumbs , Ashwani Sharma

The approximate analytical solutions of the Dirac equations with the reflectionless-type and Rosen-Morse potentials including the spin-orbit centrifugal (pseudo-centrifugal) term are obtained. Under the conditions of spin and pseudospin…

Quantum Physics · Physics 2012-05-17 Sameer M. Ikhdair , Ramazan Sever

We study the electronic states of graphene in piecewise constant potentials using the continuum Dirac equation appropriate at low energies, and a transfer matrix method. For superlattice potentials, we identify patterns of induced Dirac…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 D. P. Arovas , L. Brey , H. A. Fertig , Eun-Ah Kim , K. Ziegler

We present a new spectral scheme for analysing functions of half-integer spin-weight on the $2$-sphere and demonstrate the stability and convergence properties of our implementation. The dynamical evolution of the Dirac equation on a…

General Relativity and Quantum Cosmology · Physics 2015-08-17 Florian Beyer , Boris Daszuta , Joerg Frauendiener

Emergent quasiparticles with a Dirac dispersion in condensed matter systems can be described by the Dirac equation for relativistic electrons, in analogy with Dirac particles in high-energy physics. For example, electrons with a Dirac…

Topological photonics has emerged recently as a novel approach for realizing robust optical circuitry, and the study of nonlinear effects in topological photonics is expected to open the door for tunability of photonic structures with…

Optics · Physics 2019-12-12 Daria Smirnova , Lev Smirnov , Daniel Leykam , Yuri Kivshar

The ability to optically engineer the Dirac band and electrically control the Fermi level in two-dimensional (2D) Dirac systems, such as graphene, has significantly advanced quantum technologies. However, similar tunability has remained…

Materials Science · Physics 2025-01-29 Sobhan Subhra Mishra , Thomas CaiWei Tan , Manoj Gupta , Faxian Xiu , Ranjan Singh

In this paper, we investigate the characteristic initial value problem for the Einstein-Dirac system, a model governing the interaction between gravity and spin-$1/2$ fields. We apply Luk's strategy \cite{Luk12} and prove a semi-global…

Analysis of PDEs · Mathematics 2025-09-05 Peng Zhao , Xiaoning Wu

We present a semiclassical analysis for Dirac fields on an arbitrary spacetime background and in the presence of a fixed electromagnetic field. Our approach is based on a Wentzel-Kramers-Brillouin approximation, and the results are analyzed…

General Relativity and Quantum Cosmology · Physics 2023-02-16 Marius A. Oancea , Achal Kumar

We consider the dynamics of relativistic spin-half particles in quantum graphs with transparent branching points. The system is modeled by combining the quantum graph concept with the one of transparent boundary conditions applied to the…

Quantum Physics · Physics 2020-07-01 J. R. Yusupov , K. K. Sabirov , Q. U. Asadov , M. Ehrhardt , D. U. Matrasulov

Topological quantum matter and spintronics research have been developed to a large extent independently. In this Review we discuss a new role that the antiferromagnetic order has taken in combining topological matter and spintronics. This…

Mesoscale and Nanoscale Physics · Physics 2017-04-06 L. Šmejkal , T. Jungwirth , J. Sinova

The interband optical absorption of linearly polarised light by two-dimensional (2D) semimetals hosting tilted and anisotropic Dirac cones in the bandstructure is analysed theoretically. Super-critically tilted (type-II) Dirac cones are…

Mesoscale and Nanoscale Physics · Physics 2022-06-09 A. Wild , E. Mariani , M. E. Portnoi
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