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Related papers: Positron potential and wavefunction in LaFeAsO

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Two dimensional angular correlation of the positron annihilation radiation (2D-ACAR) spectra are measured for $\mathrm{LaB}_6$ along high symmetry directions and compared with first principle calculations based on density functional theory…

The two-dimensional measurement of the angular correlation of the positron annihilation radiation (2D-ACAR) is a powerful tool to investigate the electronic structure of materials. Here we report on the first results obtained with the new…

Strongly Correlated Electrons · Physics 2015-06-15 Josef Andreas Weber , Peter Boni , Hubert Ceeh , Michael Leitner , Christoph Hugenschmidt

Angular Correlation of Annihilation Radiation (ACAR) is a well established technique for the investigation of the electric structure. A major limitation of ACAR studies is the available positron flux at a small spot on the sample. Fore this…

Instrumentation and Detectors · Physics 2012-10-15 Hubert Ceeh , Josef-Andreas Weber , Michael Leitner , Peter Böni , Christoph Hugenschmidt

The electronic structure of vanadium measured by Angular Correlation of electron-positron Annihilation Radiation (ACAR) is compared with the predictions of the combined Density Functional and Dynamical Mean-Field Theory (DMFT).…

The annihilation parameters of positrons with electrons in different shells of Argon, Iron and Copper atoms are calculated below the positronium (Ps) formation thresholds. Quite accurate ab initio calculations of the bound state…

Atomic Physics · Physics 2007-11-06 M. A. Abdel-Raouf , M. M. Abdel-Mageed , S. Y. El-Bakry

The measurement of the 2D-Angular Correlation of Electron Positron Annihilation Radiation (ACAR) provides unique information about the bulk electronic structure of single crystals. We set up a new prototype for 2D-ACAR measurements using…

Instrumentation and Detectors · Physics 2024-12-23 Kilian Brenner , Francesco Guatieri , Christoph Hugenschmidt

Different ways of dealing with one-dimensional (1D) spectra, measured e.g. in the Compton scattering or angular correlation of positron annihilation radiation (ACAR) experiments are presented. On the example of divalent hexagonal close…

Materials Science · Physics 2007-05-23 G. Kontrym-Sznajd , M. Samsel-Czekala

In this study, a fully self-consistent method was developed to obtain the wave functions of the positron and electrons in molecules simultaneously. The wave function of a positron at room temperature , with a characteristic energy of…

Atomic and Molecular Clusters · Physics 2020-06-24 Lin Tang , Xiaoguang Ma , Jipeng Sui , Meishan Wang , Chuanlu Yang

Calculations of the relaxation energy, contact pair-correlation function, and annihilating-pair momentum density for a single positron immersed in a homogeneous electron gas are presented. We achieve an accurate description of the…

Mesoscale and Nanoscale Physics · Physics 2011-01-20 N. D. Drummond , P. Lopez Rios , C. J. Pickard , R. J. Needs

A brief review is given of recent positron studies of metal and semiconductor nanocrystals. The prospects offered by positron annihilation as a sensitive method to access nanocrystal (NC) properties are described and compared with other…

Materials Science · Physics 2007-10-11 S. W. H. Eijt , B. Barbiellini , A. J. Houtepen , D. Vanmaekelbergh , P. E. Mijnarends , A. Bansil

Positron physics touches on a wide-ranging variety of fields from materials science to medical imaging to high energy physics. In this paper we present the development of a flexible positron annihilation spectrometer appropriate for the…

Physics Education · Physics 2018-08-01 Jason Engbrecht , Nathaniel Hillson

We perform spin-polarized two-dimensional angular correlation of annihilation radiation (2D-ACAR) calculations for the recently predicted ZrCo$_2$Sn-Weyl Heusler compound within the density functional theory using the generalized gradient…

Strongly Correlated Electrons · Physics 2018-06-12 D. Benea , A. Östlin , J. A. Weber , E. Burzo , L. Chioncel

Using the combined Density Functional and Dynamical Mean Field theory we study relativistic corrections to the Fermi surface of palladium. We find indeed that relativistic corrections create a small hole pockets at the $L$-symmetry points.…

Strongly Correlated Electrons · Physics 2021-11-05 Michael Sekania , Andreas Östlin , Wilhelm H. Appelt , S. B. Dugdale , Liviu Chioncel

Within the last decade powerful methods have been developed to study surfaces using bright low-energy positron beams. These novel analysis tools exploit the unique properties of positron interaction with surfaces, which comprise the absence…

Materials Science · Physics 2016-11-15 Christoph Hugenschmidt

Time- and angle-resolved extreme ultraviolet photoemission spectroscopy is used to study the electronic structure dynamics in BaFe$_2$As$_2$ around the high-symmetry points $\Gamma$ and $M$. A global oscillation of the Fermi level at the…

We consider an electron-acoustic phonon coupling mechanism associated with the dependence of crystal dielectric permittivity on the strain (the so-called Pekar mechanism) in nanostructures characterized by strong confining electric fields.…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 B. A. Glavin , V. A. Kochelap , T. L. Linnik , K. W. Kim

Annihilation spectra are presented for aromatic and heterocyclic ring molecules resolved as a function of incident positron energy using a trap-based positron beam. Comparisons with the vibrational mode spectra yield positron-molecule…

We discuss the electronic structure, lattice dynamics and electron-phonon interaction of newly discovered superconductor LaO$_{0.5}$F$_{0.5}$BiS$_{2}$ using density functional based calculations. A strong Fermi surface nesting at…

Superconductivity · Physics 2015-03-20 Xiangang Wan , Hang-Chen Ding , Sergey Y. Savrasov , Chun-Gang Duan

Polarons are composite quasiparticles formed by excess charges and the accompanying lattice distortions in solids, and play a critical role in transport, optical, and catalytic properties of semiconductors and insulators. The standard…

Materials Science · Physics 2026-03-25 Zhenbang Dai , Donghwan Kim , Jon Lafuente-Bartolome , Feliciano Giustino

Within the framework of a model representing the potential of a graphene sheet U(z) as an electro-neutral layer formed by smeared carbon atoms, the effect of this potential on spectral characteristics of atoms adsorbed on a graphene sheet…

Atomic Physics · Physics 2013-10-02 A. S. Baltenkov , V. A. Pikhut
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