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Abstract Quantum electronics has significantly evolved over the last decades. Where initially the clear focus was on light–matter interactions, nowadays approaches based on the electron’s wave nature have solidified themselves a...
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Abstract Quantum electronics has significantly evolved over the last decades. Where initially the clear focus was on light–matter interactions, nowadays approaches based on the electron’s wave nature have solidified themselves as additional focus areas. This development is largely driven by continuous advances in electron quantum optics, electron based quantum information processing, electronic materials, and nanoelectronic devices and systems. The pace of research in all of these areas is astonishing and is accompanied by substantial theoretical and experimental advancements. What is particularly exciting is the fact that the computational methods, together with broadly available large-scale computing resources, have matured to such a degree so as to be essential enabling technologies themselves. These methods allow to predict, analyze, and design not only individual physical processes but also entire devices and systems, which would otherwise be very challenging or sometimes even out of reach with conventional experimental capabilities. This review is thus a testament to the increasingly towering importance of computational methods for advancing the expanding field of quantum electronics. To that end, computational aspects of a representative selection of recent research in quantum electronics are highlighted where a major focus is on the electron’s wave nature. By categorizing the research into concrete technological applications, researchers and engineers will be able to use this review as a source for inspiration regarding problem-specific computational methods.
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News editors obtained the following quote from the background information supplied by the inventors:
“Pressure vessels are commonly used for containing a variety of gases or fluids under pressure, such as
hydrogen, oxygen, natu...
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News editors obtained the following quote from the background information supplied by the inventors:
“Pressure vessels are commonly used for containing a variety of gases or fluids under pressure, such as
hydrogen, oxygen, natural gas, nitrogen, propane and other fuels, for example. Generally, pressure vessels
can be of any size or configuration. The vessels can be heavy or light, single-use (e.g., disposable), reusable,
subjected to high pressures (greater than 50 psi, for example), low pressures (less than 50 psi, for example),
or used for storing fluids at elevated or cryogenic temperatures, for example.
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The following quote was obtained by the news editors from the background information supplied by
the inventors: “Transmission of dual frequency pulse complexes composed of a high frequency (HF) and
low frequency (LF) pulse for ...
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The following quote was obtained by the news editors from the background information supplied by
the inventors: “Transmission of dual frequency pulse complexes composed of a high frequency (HF) and
low frequency (LF) pulse for imaging of nonlinear propagation and scattering parameters of an object is
described in U.S. Pat. Nos. 7,641,613; 8,038,616; 8,550,998 and 9,291,493. The methods also provide
suppression of multiple scattering noise (reverberation noise) and improved imaging of linear and nonlinear
scatterers. Imaging with coherent acoustic pressure waves is shown as an example, but it is clear that the
methods are also useful for imaging with all types of coherent wave imaging, such as shear elastic waves and
electromagnetic waves. The cited methods require estimation of one or both of a nonlinear propagation
delay (NPD) and a nonlinear propagation pulse form distortion (PFD) which both are challenging tasks.
The present invention describes new methods and instrumentation for improved estimation of both the NPD
and the PFD, and provides scatter images with reduced multiple scattering noise and images of nonlinear
scatterers. Combined with measurements with zero LF pulse, the invention also provides estimates of linear
propagation and scattering parameters, that combined with the estimates of nonlinear parameters is used
to obtain a thermo-elastic description of the object.”
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News editors obtained the following quote from the background information supplied by the inventors:
“Space based gravitational wave detection applications typically require measuring picometer variations
over distances of more...
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News editors obtained the following quote from the background information supplied by the inventors:
“Space based gravitational wave detection applications typically require measuring picometer variations
over distances of more than 1 million kilometers, thus requiring precision interferometry with a low noise,
high power laser source. These types of laser sources, due to their low noise properties, may be used
as stable laser sources for laser metrology, laser spectroscopy and timing applications. These types of
lasers may also be used as single frequency, low noise seed sources for high power continuous wave or
pulsed laser systems for measuring wind, spectroscopy and metrology. Typical laser systems for these
applications may use a wavelength of 1064 nm. Neodymium doped Yttrium Aluminum Garnet (Nd:YAG)
non-planar ring oscillators (NPROs) have been known to have very good frequency noise performance in solid state laser applications. Unidirectional NPROs with the use of an applied external magnetic field
advantageously have no standing wave, which avoids spatial hole burning, exhibit higher single mode power
than linear resonators, and because they are monolithic, exhibit excellent frequency stability and tolerance
to misalignment. Current NPROs are typically based on a Nd:YAG crystal with approximate dimensions
of ˜1 cm x ˜1 cm x ˜2 mm, and are pumped with a multimode pump laser diode at 808 nm to produce
approximately 100˜800 mW of output power. FIG. 1 shows a schematic diagram of a typical NPRO.
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The validity of Shkarofsky's dielectric tensor is extended by taking the strictly weakly relativistic limit and removing, when possible, assumptions on the wavenumbers along and across the ambient magnetic field, k(parallel to) an...
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The validity of Shkarofsky's dielectric tensor is extended by taking the strictly weakly relativistic limit and removing, when possible, assumptions on the wavenumbers along and across the ambient magnetic field, k(parallel to) and k(perpendicular to). An approximation of the time integral is retained, but is shown to be valid under more benign assumptions than those of quasiperpendicular incidence and small Larmor radius. The increased generality with respect to k(parallel to) permits to handle cases of comparable Doppler and relativistic widths of electron cyclotron resonances. The tensor also suits Bernstein waves, as it captures both their natural large k(perpendicular to) and the finite k(parallel to) that is typical of some mode conversions, or acquired as a consequence of the large k(perpendicular to) when propagating in curved magnetic fields. Finally, relativistic corrections to the optimal angle for the ordinary-extraordinary Bernstein mode conversion are presented. (C) 2007 American Institute of Physics.
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We fabricated decananometer-gate pseudomorphic In/sub 0.52/Al/sub 0.48/As/In/sub 0.7/Ga/sub 0.3/As high-electron mobility transistors (HEMTs) with a very short gate-channel distance. We obtained a cutoff frequency f/sub T/ of 562 ...
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We fabricated decananometer-gate pseudomorphic In/sub 0.52/Al/sub 0.48/As/In/sub 0.7/Ga/sub 0.3/As high-electron mobility transistors (HEMTs) with a very short gate-channel distance. We obtained a cutoff frequency f/sub T/ of 562 GHz for a 25-nm-gate HEMT. This f/sub T/ is the highest value ever reported for any transistor. The ultrahigh f/sub T/ of our HEMT can be explained by an enhanced electron velocity under the gate, which was a result of reducing the gate-channel distance.
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A low-temperature electron diffraction Study has been carried out on ThAsSe to search for evidence of structural disorder associated with the low-temperature non-magnetic Kondo effect. A highly structured and extremely complex cha...
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A low-temperature electron diffraction Study has been carried out on ThAsSe to search for evidence of structural disorder associated with the low-temperature non-magnetic Kondo effect. A highly structured and extremely complex characteristic diffuse intensity distribution has been observed at low temperature and interpreted in terms of a gradual charge density wave type phase transition upon lowering of temperature involving disordered As-As dimerization within (001) planes. Plausible models of the proposed As-As dimerization have been obtained using a group theoretical approach. (C) 2003 Elsevier Inc. All rights reserved. [References: 31]
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We report the dependence of photo-oxidation (i.e., the formation of As2O3 microcrystals) on Ag (or Cu) content in Ag-doped As2Se3 and Cu-doped As2Se3 films. These chalcogenide films were prepared by thermal evaporation and photodo...
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We report the dependence of photo-oxidation (i.e., the formation of As2O3 microcrystals) on Ag (or Cu) content in Ag-doped As2Se3 and Cu-doped As2Se3 films. These chalcogenide films were prepared by thermal evaporation and photodoping, and their film surface was illuminated in air with an Ar laser beam of a wavelength of 0.5145 mu m. From viewpoint of applications, we paid attention to the probability and the beginning optical intensity of the As2O3 microcrystals formation, and the photodarkening effect as a function of Ag (Cu) content. It has been confirmed that the addition of metals Cu or Ag into As2Se3 films is very useful in for suppressing or weakening such a harmful oxidation reaction. It has also been found that there is a distinct difference in these properties between Ag-As2Se3 and Cu-As2Se3 films, which is attributed to the difference in the coordinate number between Ag and Cu atoms. (c) 2007 Elsevier B.V. All rights reserved.
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The Pegasus Toroidal Experiment was developed to explore the physics limits of plasma operation as the aspect ratio (A) approaches unity. Initial experiments on the device found that access to high normalized current and toroidal ...
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The Pegasus Toroidal Experiment was developed to explore the physics limits of plasma operation as the aspect ratio (A) approaches unity. Initial experiments on the device found that access to high normalized current and toroidal beta was limited by the presence of large-scale tearing modes. Major upgrades have been conducted of the facility to provide the control tools necessary to mitigate these resistive modes. The upgrades include new programmable power supplies, new poloidal field coils and increased, time-variable toroidal field. First ohmic operations with the upgraded system demonstrated position and current ramp-rate control, as well as improvement in ohmic flux consumption from 2.9 MA Wb(-1) to 4.2 MA Wb(-1). The upgraded experiment will be used to address three areas of physics interest. First, the kink and ballooning stability boundaries at low A and high normalized current will be investigated. Second, clean, high-current plasma sources will be studied as a helicity injection tool. Experiments with two such sources have produced toroidal currents three times greater than predicted by geometric field line following. Finally, the use of electron Bernstein waves to heat and drive current locally will be studied at the I MW level; initial modelling indicates that these experiments are feasible at a frequency of 2.45 GHz.
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Reporters obtained the following quote from the background information supplied by the inventors:
“Aesthetic medicine includes all treatments resulting in enhancing a visual appearance and satisfaction of
the patient. Patients ...
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Reporters obtained the following quote from the background information supplied by the inventors:
“Aesthetic medicine includes all treatments resulting in enhancing a visual appearance and satisfaction of
the patient. Patients want to minimize all imperfections including body shape and effects of natural aging.
Indeed, patients request quick, non-invasive procedures providing satisfactory results with minimal risks.
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