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Related papers: Optical properties of cubic and rhombohedral GeTe

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ZrTe$_5$ is considered a potential candidate for either a Dirac semimetal or a topological insulator in close proximity to a topological phase transition. Recent optical conductivity results motivated a two-band model with a conical…

Mesoscale and Nanoscale Physics · Physics 2020-10-26 Corentin Morice , Elias Lettl , Thilo Kopp , Arno P. Kampf

The effect of Non-centrosymmetricity on electronic and optical properties has been investigated using grid based projector augmented wave method code GPAW. The calculation of band gap using GLLB-SC which improves on the exchange potential…

Materials Science · Physics 2020-12-10 Tewodros Eyob , Kenate Nemera , Lemi Demeyu

The extreme electro-optical contrast between crystalline and amorphous states in phase change materials is routinely exploited in optical data storage and future applications include universal memories, flexible displays, reconfigurable…

We study the optical properties of the layered rhodium oxide K0.49RhO2, which is isostructural to the thermoelectric material NaxCoO2. The optical conductivity shows broad interband transition peaks as well as a low-energy Drude-like…

Strongly Correlated Electrons · Physics 2011-08-09 R. Okazaki , Y. Nishina , Y. Yasui , S. Shibasaki , I. Terasaki

Structural and Optical properties of the (Na0.5 K0.5)y Li 1-y NbO3 (y = 0.934 & 0.936) ceramics have been explored in terms of the X-Ray diffraction patters, Rietveld analysis, UV-Vis spectroscopy, and Kubelka-Munk functions. Rietveld…

Materials Science · Physics 2015-06-17 S. K. Mishra , R. K. Mishra , Kumar Brajesh , Rajyavardhan Ray , A. K. Himanshu , N. K. Singh

The optical properties of the superconducting single crystal Rb$_{0.8}$Fe$_{1.68}$Se$_2$ with $T_{c}$ $\simeq$ 31 K have been measured over a wide frequency range in the $ab$ plane. We found that the optical conductivity is dominated by a…

Superconductivity · Physics 2015-06-19 B. Xu , Y. M. Dai , J. Han , K. Wang , R. Yang , Y. X. Yang , W. Zhang , H. Xiao , X. G. Qiu

Many properties of layered materials change as they are thinned from their bulk forms down to single layers, with examples including indirect-to-direct band gap transition in 2H semiconducting transition metal dichalcogenides as well as…

We present an angle-resolved photoemission study of a ternary phase change material, namely Ge2Sb2Te5, epitaxially grown on Si(111) in the metastable cubic phase. The observed upper bulk valence band shows a minimum at Gamma-bar being 0.3…

Knowing the electronic structure of a material is essential in energy applications to rationalize its performance and propose alternatives. Materials for thermoelectric applications are generally small-gap semiconductors and should have a…

Materials Science · Physics 2020-03-09 A. Berche , M. Talla Noutack , M. -L. Doublet , P. Jund

Polycrystalline Sb 2 Te 3-x Se x (0.0 < x < 1.0) samples were synthesized by the solid state reaction method. The structural analysis showed that up to the maximal concentration of Se, the samples possess the Rhombohedral crystal symmetry…

We calculated the effects of structural distortions on the electronic structure of carbon nanotubes. The key modification of the electronic structure brought about by bending a nanotube involves an increased mixing of $\sigma$ and…

Materials Science · Physics 2019-08-17 Alain Rochefort , Dennis R. Salahub , Phaedon Avouris

We present a comparative study of the optical and material property dependences of VCSELs on Ge or GaAs substrate thicknesses and epitaxy process conditions. It was found that adjusting the Ge substrate thickness and optimizing the epitaxy…

Materials Science · Physics 2025-08-12 Wenhan Dong , Zeyu Wan , Yun-Cheng Yang , Chao-Hsin Wu , Yiwen Zhang , Rui-Tao Wen , Guangrui Xia

$\alpha$-GeTe(111) is a non-centrosymmetric ferroelectric (FE) material for which a significative lattice distortion combined with a strong spin-orbit interaction gives rise to giant Rashba split states in the bulk and at the surface, which…

The microscopic properties of the interactions of relativistic electrons were observed to alter when macro-conditions, such as the crystal vacuum, were changed. A qualitative explanation of the phenomenon is given.

High Energy Physics - Experiment · Physics 2007-05-23 A. Aganyants

Progress in electron-beam spectroscopies has recently enabled the study of optical excitations with combined space, energy and time resolution in the nanometer, millielectronvolt and femtosecond domain, thus providing unique access into…

Optics · Physics 2019-11-13 Albert Polman , Mathieu Kociak , F. Javier García de Abajo

The development of semiconductor electronics is shortly reviewed, beginning with the development of germanium devices (band gap $E_g=0.66$ eV) after world war II. Quickly a tendency to alternative materials with wider band gap became…

Materials Science · Physics 2017-11-06 D. Klimm

Electronic band structure and optical properties of zinc monochalcogenides with zinc-blende- and wurtzite-type structures were studied using the ab initio density functional method within the LDA, GGA, and LDA+U approaches. Calculations of…

Soft Condensed Matter · Physics 2009-11-13 S. Zh. Karazhanov , P. Ravindran , A. Kjekshus , H. Fjellvag , B. G. Svensson

We develop the tight-binding model to study electronic and optical properties of graphane. The strong sp3 chemical bondings among the carbon and hydrogen atoms induce a special band structure and thus lead to the rich optical excitations.…

Materials Science · Physics 2016-10-31 M. H. Lee , H. C. Chung , J. M. Lu , C. P. Chang , M. F. Lin

The effects of edge covalent functionalization on the structural, electronic and optical properties of elongated armchair graphene nanoflakes (AGNFs) are analyzed in detail for a wide range of terminations, within the ramework of…

Mesoscale and Nanoscale Physics · Physics 2015-02-26 Caterina Cocchi , Deborah Prezzi , Alice Ruini , Marilia J. Caldas , Elisa Molinari

Determining the electronic and dielectric properties of water at high pressure and temperature is an essential prerequisite to understand the physical and chemical properties of aqueous environments under supercritical conditions, e.g. in…

Materials Science · Physics 2014-08-07 Ding Pan , Quan Wan , Giulia Galli