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Related papers: First-principles calculation of x-ray dichroic spe…

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When polarized light is absorbed by an atom, the excited atomic system carries information about the initial polarization of light. For the light that carries an orbital angular momentum, or the twisted light, the polarization states are…

Quantum Physics · Physics 2020-05-18 Andrei Afanasev , Carl E. Carlson , Hao Wang

Reliable atomic data have been computed for the spectral modeling of the nitrogen K lines, which may lead to useful astrophysical diagnostics. Data sets comprise valence and K-vacancy level energies, wavelengths, Einstein $A$-coefficients,…

High Energy Astrophysical Phenomena · Physics 2014-11-20 J. Garcia , T. R. Kallman , M. Witthoeft , E. Behar , C. Mendoza , P. Palmeri , P. Quinet , M. A. Bautista , M. Klapisch

We present briefly the first results obtained by the application of the KYNREFREV-reverberation model, which is ready for its use in XSPEC. This model computes the time dependent reflection spectra of the disc as a response to a flash of…

High Energy Astrophysical Phenomena · Physics 2017-01-17 M. D. Caballero-Garcia , M. Dovciak , I. Papadakis , A. Epitropakis , J. Svoboda , E. Kara , V. Karas

A first-principles theory of resonant magnetic scattering of x rays is presented. The scattering amplitudes are calculated using a standard time-dependent perturbation theory to second order in the electron-photon interaction vertex. In…

Strongly Correlated Electrons · Physics 2009-11-10 E. Arola , M. Horne , P. Strange , H. Winter , Z. Szotek , W. M. Temmerman

Raman spectroscopy is an advantageous method for studying the local structure of materials, but the interpretation of measured spectra is complicated by the presence of oblique phonons in polycrystals of polar materials. Whilst group theory…

We develop a formalism for the calculation of the macroscopic dielectric response of composite systems made of particles of one material embedded periodically within a matrix of another material, each of which is characterized by a well…

We apply spin-squeezing techniques to identify and quantify highly multi-partite photonic entanglement in polarization-squeezed light. We consider a practical single-mode scenario, and find that Wineland-criterion polarization squeezing…

Quantum Physics · Physics 2014-09-24 Morgan W. Mitchell , Federica A. Beduini

The extended boundary condition method can be formulated to study plane-wave scattering by an ellipsoid composed of an orthorhombic dielectric-magnetic material whose relative permittivity dyadic is a scalar multiple of its relative…

Optics · Physics 2019-05-22 H. M. Alkhoori , A. Lakhtakia , J. K. Breakall , C. F. Bohren

By including phonon-assisted transitions within plane-wave DFT methods for calculating the X-ray absorption spectrum (XAS) we obtain the Al K-edge XAS at 300 K for two Al$_2$O$_3$ phases. The 300 K XAS reproduces the pre-edge peak for…

Materials Science · Physics 2022-06-29 Angela F. Harper , Bartomeu Monserrat , Andrew J. Morris

In this paper the authors analyse near-edge absorption of x rays in noncentrosymmetric crystals. The work is motivated by recent observations of x-ray dichroic effects which stems from parity-nonconserving electron interactions. We provide…

Condensed Matter · Physics 2009-11-07 Paolo Carra , Andres Jerez , Ivan Marri

The room temperature X-ray photoemission spectrum of the ferromagnetic compound UCu$_2$Si$_2$ (T$_C$ = 100 K) was measured using an Al K$_{\alpha}$ source. Related theoretical spectra were computed from densities of electronic states…

Strongly Correlated Electrons · Physics 2025-03-27 J. A. Morkowski , G. Chełkowska , M. Werwiński , A. Szajek , R. Troć , C. Neise

We calculate the time dependent electron distribution under the assumption of continuous injection of new relativistic particles, and assuming radiative cooling (by sinchrotron and inverse Compton) and particle escape. Resulting photon…

Astrophysics · Physics 2007-05-23 Marco Chiaberge , Gabriele Ghisellini

We present a new first-principle theory for the calculation of the macroscopic second-order susceptibility chi^(2), based on the Time-Dependent Density-Functional Theory approach. Our method allows to include straightforwardly the many-body…

Materials Science · Physics 2010-01-15 Eleonora Luppi , Hannes Hübener , Valérie Véniard

We investigate how the direction of polarized light can affect the dichroism pattern seen in angle-resolved photoemission spectroscopy. To this end, we prepared a sample composed of highly-oriented Bi(111) micro-crystals that…

Strongly Correlated Electrons · Physics 2020-07-07 Y. Ishida , D. Chung , J. Kwon , Y. S. Kim , S. Soltani , Y. Kobayashi , A. J. Merriam , L. Yu , C. Kim

Using the general approach of Lax for multiple scattering of waves a 2x2 covariant expression for the reflectivity of polarized slow neutrons of a magnetic layer structure of arbitrary complexity is given including polarization effects of…

Other Condensed Matter · Physics 2015-03-04 L Deák , L. Bottyán , D. L. Nagy , H. Spiering

Theory of light absorption and circular photocurrent in Weyl semimetals is developed for arbitrary large light intensities with account for both elastic and inelastic relaxation processes of Weyl fermions. The direct optical transition rate…

Mesoscale and Nanoscale Physics · Physics 2019-10-21 N. V. Leppenen , E. L. Ivchenko , L. E. Golub

We devise a theoretical description for the response of nitrogen molecules (N2) to ultrashort and intense x rays from the free electron laser (FEL) Linac Coherent Light Source (LCLS). We set out from a rate-equation description for the…

We present a detailed model of the discrete X-ray spectroscopic features expected from steady-state, low-density photoionized plasmas. We apply the Flexible Atomic Code (FAC) to calculate all of the necessary atomic data for the full range…

Astrophysics · Physics 2007-05-23 A. Kinkhabwala , E. Behar , M. Sako , M. F. Gu , S. M. Kahn , F. B. S. Paerels

A finite element-based modal formulation of diffraction of a plane wave by an absorbing photonic crystal slab of arbitrary geometry is developed for photovoltaic applications. The semi-analytic approach allows efficient and accurate…

The linear optical absorption spectra of three isomers of planar boron cluster B$_{13}$ are calculated using time-dependent spin-polarized density functional approach. The geometries of these cluster are optimized at the B3LYP/6-311+G*…

Atomic and Molecular Clusters · Physics 2013-02-12 Ravindra Shinde , Meenakshi Tayade
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