English
Related papers

Related papers: Spawning rings of exceptional points out of Dirac …

200 papers

While "Dirac cone" dispersions can only be meaningfully defined in two dimensional (2D) systems, the notion of a Dirac point can be extended to three dimensional (3D) classical wave systems. We show that a simple cubic photonic crystal…

Materials Science · Physics 2013-11-01 Xueqin Huang , Fengming Liu , C. T. Chan

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

The phenomenon of spin-dependent quantum scattering in two-dimensional (2D) pseudospin-1/2 Dirac materials leading to a relativistic quantum chimera was recently uncovered. We investigate spin-dependent Dirac electron optics in 2D…

Mesoscale and Nanoscale Physics · Physics 2024-08-23 Li-Li Ye , Chen-Di Han , Ying-Cheng Lai

We consider the scattering of electromagnetic waves by non-spherical dielectric resonators and reveal that it can be linked to the exceptional points underpinned by the physics of non-Hermitian systems. We demonstrate how symmetry breaking…

We investigate the emergence of extra Dirac points in the electronic structure of a periodically spaced barrier system, i.e., a superlattice, on single-layer graphene, using a Dirac-type Hamiltonian. Using square barriers allows us to find…

Mesoscale and Nanoscale Physics · Physics 2015-05-18 M. Barbier , P. Vasilopoulos , F. M. Peeters

Unpinned Dirac points (DPs) are nodal point degeneracies that occur at generic momentum points lacking high symmetry, often exhibiting characteristics typically forbidden by symmetry. While this phenomenon has been observed in solid-state…

Optics · Physics 2025-02-20 Chang-Hwan Yi , Kyoung-Min Kim

The type-II Dirac cone is a special feature of the band structure, whose Fermi level is represented by a pair of crossing lines. It has been demonstrated that such a structure is useful for investigating topological edge solitons, and more…

Optics · Physics 2024-09-09 Qian Tang , Milivoj R. Belić , Hua Zhong , Meng Cao , Yongdong Li , Yiqi Zhang

The energy spectra for the tight-binding models on the Lieb and kagom\'e lattices both exhibit a flat band. We present a model which continuously interpolates between these two limits. The flat band located in the middle of the three-band…

Mesoscale and Nanoscale Physics · Physics 2020-01-31 Lih-King Lim , Jean-Noël Fuchs , Frédéric Piéchon , Gilles Montambaux

The main concepts of the recently developed approach to singular problems of quantum mechanics are extended to the Dirac particle in the Coulomb field of a point-like nucleus with its charge Z>137. The reflection and transmission…

High Energy Physics - Theory · Physics 2007-05-23 A. E. Shabad

We present a unified theory of charge carrier transport in 2D Dirac systems with broken mirror inversion and time-reversal symmetries (e.g., as realized in ferromagnetic graphene). We find that the entanglement between spin and pseudospin…

Mesoscale and Nanoscale Physics · Physics 2018-09-21 Manuel Offidani , Aires Ferreira

After the discovery of graphene and its many fascinating properties, there has been a growing interest for the study of "artificial graphenes". These are totally different and novel systems which bear exciting similarities with graphene.…

Mesoscale and Nanoscale Physics · Physics 2019-06-20 Gilles Montambaux

Hybridization of highly itinerant Dirac electrons with localized flat-band states is predicted to yield emergent phenomena such as exotic heavy-fermion behaviour. Epitaxial graphene on two-dimensional adsorbate structures on SiC(0001),…

Dirac materials are of great interest as condensed matter realizations of the Dirac and Weyl equations. In particular, they serve as a starting point for the study of topological phases. This physics has been extensively studied in…

Mesoscale and Nanoscale Physics · Physics 2020-08-11 P. Sathish Kumar , Igor F. Herbut , R. Ganesh

This study is devoted to the profound implications of tilted Dirac cones on the quantum transport properties of two-dimensional (2D) Dirac materials. These materials, characterized by their linear conic energy dispersions in the vicinity of…

Mesoscale and Nanoscale Physics · Physics 2024-10-30 Rasha Al-Marzoog , Ali Rezaei , Zahra Noorinejad , Mohsen Amini , Ebrahim Ghanbari-Adivi , S. A. Jafari

We generalize a proposal by Sorensen et al. [Phys. Rev. Lett. 94, 086803 (2005)] for creating an artificial magnetic field in a cold atom system on a square optical lattice. This leads us to an effective lattice model with tunable spatially…

Quantum Gases · Physics 2018-12-13 Malcolm P. Kennett , Nazanin Komeilizadeh , Kamran Kaveh , Peter M. Smith

Type-II Dirac points (DPs), which occur at the intersection of strongly tilted and touching energy bands, exhibit many intriguing physical phenomena fundamentally different from the non-tilted type-I counterparts. Over the past decade,…

Odd numbers of Dirac points and helical states can exist at edges (surfaces) of two-dimensional (three-dimensional) topological insulators. In the bulk of a one-dimensional lattice (not an edge) with time reversal symmetry, however, a no-go…

Mesoscale and Nanoscale Physics · Physics 2013-05-24 Sheng-Nan Ji , Bang-Fen Zhu , Ren-Bao Liu

Dirac semimetals, the materials featured with discrete linearly crossing points (called Dirac points) between four bands, are critical states of topologically distinct phases. Such gapless topological states have been accomplished by a…

Materials Science · Physics 2020-01-20 Xiangxi Cai , Liping Ye , Chunyin Qiu , Meng Xiao , Rui Yu , Manzhu Ke , Zhengyou Liu

We demonstrate that, apart from the chiral anomaly, Dirac semimetals possess another quantum anomaly, which we call the mirror anomaly, and which manifests in a singular response of the Dirac semimetal to an applied magnetic field. Namely,…

Mesoscale and Nanoscale Physics · Physics 2018-01-09 A. A. Burkov

The pi bands of epitaxially grown graphene are studied by using high resolution angle resolved photoemission spectroscopy. Clear deviations from the conical dispersion expected for massless Dirac fermions and an anomalous increase of the…

Materials Science · Physics 2008-07-30 S. Y. Zhou , D. A. Siegel , A. V. Fedorov , A. Lanzara