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Semi-Dirac fermions are massless in one direction and massive in the perpendicular directions. Such quasiparticles have been proposed in various contexts in condensed matter. Using first principles calculations, we identify a pair of…

Materials Science · Physics 2025-11-13 Alaska Subedi , Kamran Behnia

A semi-Dirac cone refers to a peculiar type of dispersion relation that is linear along the symmetry line but quadratic in the perpendicular direction. Here, I demonstrate that a photonic crystal consisting of a square array of elliptical…

Optics · Physics 2014-01-23 Ying Wu

We study transport across p-n junctions of gapped two-dimensional semi-Dirac materials: nodal semimetals whose energy bands disperse quadratically and linearly along distinct crystal axes. The resulting electronic properties --- relevant to…

Mesoscale and Nanoscale Physics · Physics 2017-07-26 K. Saha , R. Nandkishore , S. A. Parameswaran

The c-axis optical conductivity and d.c. resistivity are calculated within the t-J model assuming that the interlayer hopping is incoherent. Use is made of numerical results for spectral functions recently obtained with the…

Strongly Correlated Electrons · Physics 2009-10-31 P. Prelovsek , A. Ramsak , I. Sega

Polarizability plays an essential role in characterizing key phenomena, such as the screening effects, collective excitations, and dielectric functions present in the system. In three-dimensional materials, it typically comprises an…

Mesoscale and Nanoscale Physics · Physics 2025-10-15 Vivek Pandey , Snehasish Nandy , Pankaj Bhalla

The coherent charge transport through an illuminated graphene ribbon is studied as function of electronic doping, frequency and strength of the electromagnetic driving, for monochromatic circularly polarized light. We focus on the DC…

Mesoscale and Nanoscale Physics · Physics 2017-12-13 Jonathan Atteia , Jens. H. Bardarson , Jérome Cayssol

We analytically calculate the intrinsic longitudinal and transverse optical conductivities of electronic systems which govern by a modified-Dirac fermion model Hamiltonian for materials beyond graphene such as monolayer MoS$_2$ and…

Mesoscale and Nanoscale Physics · Physics 2015-06-18 Habib Rostami , Reza Asgari

Combination of electrical conductivity and optical transparency in the same material -- known to be a prerogative of only a few oxides of post-transition metals, such as In, Sn, Zn and Cd -- manifests itself in a distinctive band structure…

Materials Science · Physics 2009-11-13 J. E. Medvedeva

Motivated by experiments confirming that the optical transparency of graphene is defined through the fine structure constant and that it could be fully explained within the relativistic Dirac fermions in 2D picture, in this article we…

Strongly Correlated Electrons · Physics 2018-11-28 Horacio Falomir , Marcelo Loewe , Enrique Muñoz , Alfredo Raya

We study the imaginary part of the effective $ac$ conductivity as well as its distribution probability for vanishing losses in 2D composites. This investigation showed that the effective medium theory provides only informations about the…

Disordered Systems and Neural Networks · Physics 2009-11-07 Lotfi Zekri , Nouredine Zekri , Jean-Pierre Clerc

We investigated the properties of dichroic cholesteric liquid crystals (CLCs) being in external static magnetic field directed along helix axis. We have shown that in the case of the wavelength dependence of magneto-optic activity…

Optics · Physics 2023-05-17 A. H. Gevorgyan

Conventional transparent materials at optical frequencies have refractive index values (n) greater than unity -- most commonly between about 1 and 4. This paper explores optical phenomena made possible by using materials with refractive…

Surface topography dictates the deterministic functionality of diffraction by a surface. In order to maximize the efficiency with which a diffractive optical component, such as a grating or a diffractive lens, directs light into a chosen…

We present a kinetic equation approach to investigate dc transport properties of graphene in the diffusive regime considering long-range electron-impurity scattering. In our study, the effects of interband correlation (or polarization) on…

Materials Science · Physics 2009-11-13 S. Y. Liu , X. L. Lei , Norman J. M. Horing

Near-zero-refractive index materials display unique optical properties such as perfect transmission through distorted waveguides, cloaking, and inhibited diffraction. Compared to conventional media, they can fundamentally behave differently…

We consider superconducting properties of a two-dimensional Dirac material such as graphene under strain that produces a flat band spectrum in the normal state. We show that in the superconducting state, such a model results in a highly…

Superconductivity · Physics 2016-06-22 V. J. Kauppila , F. Aikebaier , T. T. Heikkilä

Optical metamaterials have the potential to control the flow of light at will which may lead to spectacular applications as the perfect lens or the cloaking device. Both of these optical elements require invariant effective material…

Optics · Physics 2009-09-09 Thomas Paul , Christoph Menzel , Carsten Rockstuhl , Falk Lederer

We have studied the optical conductivity of two-dimensional (2D) semiconducting transition metal dichalcogenides (STMDC) using ab-initio density functional theory (DFT). We find that this class of materials presents large optical response…

Materials Science · Physics 2013-11-06 A. Carvalho , R. M. Ribeiro , A. H. Castro Neto

We study the transversal magnetoconductivity and magnetoresistance of a massive Dirac fermion gas. This can be used as a simple model for gapped Dirac materials. In the zero-mass limit, the case of gapless Dirac semimetals is also studied.…

Mesoscale and Nanoscale Physics · Physics 2018-11-16 Viktor Könye , Masao Ogata

We study optical properties of two dimensional silicene using density functional theory based calculations. Our results on optical response property calculations show that they strongly depend on direction of polarization of light, hence…

Mesoscale and Nanoscale Physics · Physics 2012-05-24 Kamal Chinnathambi , Aparna Chakrabarti , Arup Banerjee , S. K. Deb