Spin-Resolved Mapping of Spin Contribution to Exchange-Correlation Holes

Schumann, F. O.; Winkler, C.; Kirschner, J.; Giebels, F.; Gollisch, H.; Feder, R.

doi:10.1103/physrevlett.104.087602

Cited by 26 publications

(20 citation statements)

References 16 publications

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“…This compact screening for a proton on a constrained site would be precluded by the restricted volume of the site. For example, in recent measurements in iron, the most compact of the BCC metals, the screened electronic correlation and exchange screening length, λ was confirmed to be λ = .265nm for the potential [31]. This BCC metal has lattice parameter defined by a.…”

Section: Limits To Screeningmentioning

confidence: 85%

Proton in SRF Niobium

Wallace¹,

Myneni²,

Ciovati³

et al. 2011

AIP Conference Proceedings

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Hydrogen is a difficult impurity to physically deal with in superconducting radio frequency (SRF) niobium, therefore, its properties in the metals should be well understood to allow the metal's superconducting properties to be optimized for minimum loss in the construction of resonant accelerator cavities. It is known that hydrogen is a paramagnetic impurity in niobium from NMR studies. This paramagnetism and its effect on superconducting properties are important to understand. To that end analytical induction measurements aimed at isolating the magnetic properties of hydrogen in SRF niobium are introduced along with optical reflection spectroscopy which is also sensitive to the presence of hydrogen. From the variety, magnitude and rapid kinetics found in the optical and magnetic properties of niobium contaminated with hydrogen forced a search for an atomic model. This yielded quantum mechanical description that correctly generates the activation energy for diffusion of the proton and its isotopes not only in niobium but the remaining metals for which data is available. This interpretation provides a frame work for understanding the individual and collective behavior of protons in metals. 1

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Section: Limits To Screeningmentioning

confidence: 85%

Proton in SRF Niobium

Wallace¹,

Myneni²,

Ciovati³

et al. 2011

AIP Conference Proceedings

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“…A spin-resolved (e, 2e) study revealed that it is possible to effectively separate exchange from Coulomb correlation [13,14]. A key ingredient of that work was a ferromagnetic sample.…”

mentioning

confidence: 98%

Energy Relations of Positron-Electron Pairs Emitted from Surfaces

et al. 2014

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The impact of a primary positron onto a surface may lead to the emission of a correlated positron-electron pair. By means of a lab-based positron beam we studied this pair emission from various surfaces. We analyzed the energy spectra in a symmetric emission geometry. We found that the available energy is shared in an unequal manner among the partners. On average the positron carries a larger fraction of the available energy. The unequal energy sharing is a consequence of positron and electron being distinguishable particles. We provide a model which explains the experimental findings.

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“…It is obvious that this requires the detection of correlated electron pairs, where one electron carries the signature of the involved excitation, while the other provides information on its decay. [6][7][8][9][10][11][12][13][14] This Rapid Communication presents the double-differential secondary-electron electron-energy-loss coincidence spectrum (SE2ELCS) of Al bombarded with 100-eV primary electrons. In the coincidence data, events can be distinguished in which the primary electron experiences a surface energy loss in vacuum, leading to ejection of a solid-state electron from the very surface (less than half an angstrom below the surface) that reaches the detector without traversing the solid at all.…”

mentioning

confidence: 99%

Secondary-electron emission induced byin vacuosurface excitations near a polycrystalline Al surface

et al. 2013

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The double-differential spectrum of coincidences between backscattered electrons and secondary electrons (SEs) emitted from a polycrystalline Al surface bombarded with 100-eV electrons was measured. For energy losses of the scattered electron in between the work function of Al and the bulk plasmon energy, a sharp peak is observed in the SE spectra, corresponding to ejection of a single electron near the Fermi edge receiving the full energy loss and momentum of the primary electron. This process predominantly takes place when the primary electron suffers a surface energy loss in vacuum, and leads to SE ejection from the very surface. At energy losses just above the bulk plasmon energy, a sharp transition is observed, corresponding to a sudden increase in the depth of ejection. The latter is a direct consequence of the complementarity of surface and bulk plasmons, the so-called Begrenzungs effect.When an energetic electron strikes a solid surface it may transfer part of its energy to the solid-state electrons. If the energy transfer exceeds the work function of the solid, an electron near the Fermi edge may escape over the surface barrier as a secondary electron (SE) or may in turn suffer energy losses, giving rise to the formation of a cascade of slow electrons. 1-4 The above phenomenon of electroninduced SE emission is highly relevant in a broad variety of applications but, due to a lack of spectral features in the cascade, SE emission is still far from being quantitatively understood. 5 While the different excitation channels can be easily discriminated with electron-energy-loss spectroscopy, the mechanism by which the deposited energy is dissipated away over the degrees of freedom of the solid is not easily resolvable by experiment. It is obvious that this requires the detection of correlated electron pairs, where one electron carries the signature of the involved excitation, while the other provides information on its decay. [6][7][8][9][10][11][12][13][14] This Rapid Communication presents the double-differential secondary-electron electron-energy-loss coincidence spectrum (SE2ELCS) of Al bombarded with 100-eV primary electrons. In the coincidence data, events can be distinguished in which the primary electron experiences a surface energy loss in vacuum, leading to ejection of a solid-state electron from the very surface (less than half an angstrom below the surface) that reaches the detector without traversing the solid at all. The choice of Al as the material for these investigations is motivated by the fact that the electron-solid interaction is Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.characterized by a sharp surface and bulk plasmon, making it possible to distinguish the single-and multiple-scattering regime in experimental data with the bare eye, considerably simplifying the identification of relevant ...

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Spin-Resolved Mapping of Spin Contribution to Exchange-Correlation Holes

Cited by 26 publications

References 16 publications

Proton in SRF Niobium

Proton in SRF Niobium

Energy Relations of Positron-Electron Pairs Emitted from Surfaces

Secondary-electron emission induced byin vacuosurface excitations near a polycrystalline Al surface

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