Real-space distribution of the Hall current densities and their spin polarization in nonmagnetic zinc-blende semiconductors

2012 ◽  
Vol 86 (19) ◽  
Author(s):  
Pavel Středa ◽  
Václav Drchal
Keyword(s):  
Spin Polarization ◽  
Hall Current ◽  
Real Space ◽  
Space Distribution ◽  
Zinc Blende ◽  
Current Densities

scholarly journals Tracing orbital images on ultrafast time scales

Science ◽  
2021 ◽  
pp. eabf3286
Author(s):  
R. Wallauer ◽  
M. Raths ◽  
K. Stallberg ◽  
L. Münster ◽  
D. Brandstetter ◽  
...  
Keyword(s):  
Momentum Space ◽  
Real Space ◽  
Space Distribution ◽  
Time Resolved ◽  
Pump Probe ◽  
High Laser ◽  
Probe Experiment ◽  
Electron Distributions ◽  
Space Dynamics ◽  
Pump Probe Experiment

Frontier orbitals determine fundamental molecular properties such as chemical reactivities. Although electron distributions of occupied orbitals can be imaged in momentum space by photoemission tomography, it has so far been impossible to follow the momentum-space dynamics of a molecular orbital in time, for example through an excitation or a chemical reaction. Here, we combined time-resolved photoemission using high laser harmonics and a momentum microscope to establish a tomographic, femtosecond pump-probe experiment of unoccupied molecular orbitals. We measured the full momentum-space distribution of transiently excited electrons, connecting their excited-state dynamics to real-space excitation pathways. Because in molecules this distribution is closely linked to orbital shapes, our experiment may in the future offer the possibility to observe ultrafast electron motion in time and space.

Energy-filtered electron diffraction from amorphized solids in the dedicated scanning transmission electron microscope (STEM)¶

1996 ◽  
Vol 54 ◽  
pp. 702-703
Author(s):  
A. N. Sreeram ◽  
L.-C. Qin ◽  
A. J. Garratt-Reed ◽  
L. W. Hobbs
Keyword(s):  
Electron Diffraction ◽  
Diffraction Data ◽  
Scanning Transmission Electron Microscope ◽  
Real Space ◽  
Distribution Functions ◽  
Space Distribution ◽  
Electron Diffraction Data ◽  
X Rays ◽  
Transmission Electron ◽  
Scanning Transmission

There is significant current interest in understanding the structure of aperiodic solids, such as originally crystalline material amorphized by ion implantation, impact or application of massive pressures, or deposited amorphous thin films, which occupy small volumes. Radially-averaged real-space distribution functions can be derived from diffraction data, the best of which come from thermal neutron diffraction, which inconveniently requires large volumes. Neutron data are collectable in reciprocal space out to q ≡ 2sin(Θ/2)/λ = 70 nm-1, where Θ is the scattering angle and λ the wavelength, or about twice as far as for X-rays, which also require large diffracting volumes. Electron diffraction is the only recourse for very small volumes because of the much stronger interaction of the electron, but spectra must be energy filtered to remove the large inelastic scattering component. Recently, it has been shown that useful electron diffraction data can be collected conveniently to at least q = 16 nm-1 in the VG HB5 dedicated 100-kV field-emission STEM. This contribution details our experiences with improved collection in the VG HB603 instrument operating at 250 kV.

Real-Space Distribution of Local WO4 Ordering in Negative Thermal Expansive ZrW2O8

2012 ◽  
Vol 134 (34) ◽  
pp. 13942-13945 ◽  
Author(s):  
Yukio Sato ◽  
Yasuhisa Yamamura ◽  
Kazuya Saito ◽  
Yuichi Ikuhara
Keyword(s):  
Real Space ◽  
Space Distribution

scholarly journals Ionospheric currents estimated simultaneously from CHAMP satelliteand IMAGE ground-based magnetic field measurements: a statisticalstudy at auroral latitudes

2004 ◽  
Vol 22 (2) ◽  
pp. 417-430 ◽  
Author(s):  
P. Ritter ◽  
H. Lühr ◽  
A. Viljanen ◽  
O. Amm ◽  
A. Pulkkinen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Local Time ◽  
Hall Current ◽  
Activity Index ◽  
Current System ◽  
Current Model ◽  
Field Measurements ◽  
Magnetic Field Measurements ◽  
Current Densities ◽  
The Magnetic Field

Abstract. One important contribution to the magnetic field measured at satellite altitude and at ground level comes from the external currents. We used the total field data sampled by the Overhauser Magnetometer on CHAMP and the horizontal magnetic field measurements of the IMAGE ground-based magnetometer network to study the ionospheric Hall current system in the auroral regions. For the CHAMP data a current model consisting of a series of lines and placed at a height of 110km is fitted to the magnetic field signature sampled on the passage across the polar region. The derived current distributions depend, among others, on season and on the local time of the satellite track. At dawn/dusk the auroral electrojets can be detected most clearly in the auroral regions. Their intensity and location are evidently correlated with the A E activity index. For a period of almost two years the results obtained from space and the currents determined from ground-based observations are studied. For the full IMAGE station array a newly-developed method of spherical elementary current systems (SECS) is employed to compute the 2-D equivalent current distribution, which gives a detailed picture of an area covering latitudes 60° – 80° N and 10° – 30° E in the auroral region. Generally, the current estimates from satellite and ground are in good agreement. The results of this survey clearly show the average dependence of the auroral electrojet on season and local time. This is particularly true during periods of increased auroral activity. The correlation coefficient of the results is close to one in the region of sizeable ionospheric current densities. Also the ratio of the current densities, as determined from above and below the ionosphere, is close to unity. It is the first time that the method of Hall current estimate from a satellite has been validated quantitatively by ground-based observations. Among others, this result is of interest for magnetic main field modelling, since it demonstrates that ground-based observations can be used to predict electrojet signatures in satellite magnetic field scalar data. Key words. Ionosphere (auroral Ionosphere; electric fields and currents; ionosphere-magnetosphere interactions)

scholarly journals Structure retrieval in liquid-phase electron scattering

2021 ◽  
Author(s):  
Jie Yang ◽  
J. Pedro F. Nunes ◽  
Kathryn Ledbetter ◽  
Elisa Biasin ◽  
Martin Centurion ◽  
...  
Keyword(s):  
Charged Particle ◽  
Liquid Phase ◽  
Electron Scattering ◽  
Real Space ◽  
Space Distribution ◽  
Analysis Method ◽  
The Real ◽  
Particle Pairs

A novel analysis method for the direct retrieval of the real-space distribution of charged particle pairs from liquid-phase electron scattering.

Atomic resolution imaging using the real-space distribution of electrons scattered by a crystalline material

2011 ◽  
Vol 67 (5) ◽  
pp. 487-490 ◽  
Author(s):  
Sorin Lazar ◽  
Joanne Etheridge ◽  
Christian Dwyer ◽  
Bert Freitag ◽  
Gianluigi A. Botton
Keyword(s):  
Real Space ◽  
Crystalline Material ◽  
Atomic Resolution ◽  
Space Distribution ◽  
The Real ◽  
Resolution Imaging

Formation and Real-Space Distribution of Acetophenone Dimers on H-containing Pt(111)

2021 ◽  
Vol 125 (35) ◽  
pp. 19311-19324
Author(s):  
Marvin C. Schmidt ◽  
Smadar Attia ◽  
Carsten Schröder ◽  
Ann-Katrin Baumann ◽  
Swetlana Schauermann
Keyword(s):  
Real Space ◽  
Space Distribution
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