scholarly journals Quadrature Squeezing and Geometric-Phase Oscillations in Nano-Optics

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1391
Author(s):  
Jeong Ryeol Choi
Keyword(s):  
Geometric Phase ◽  
Linear Increase ◽  
Time Behavior ◽  
Squeezed State ◽  
Periodic Oscillations ◽  
Optical Phenomenon ◽  
Dynamical Phase ◽  
Wide Range ◽  
Current Flows ◽  
Physical Phenomena

The geometric phase, as well as the familiar dynamical phase, occurs in the evolution of a squeezed state in nano-optics as an extra phase. The outcome of the geometric phase in that state is somewhat intricate: its time behavior exhibits a combination of a linear increase and periodic oscillations. We focus in this work on the periodic oscillations of the geometric phase, which are novel and interesting. We confirm that such oscillations are due purely to the effects of squeezing in the quantum states, whereas the oscillation disappears when we remove the squeezing. As the degree of squeezing increases in q-quadrature, the amplitude of the geometric-phase oscillation becomes large. This implies that we can adjust the strength of such an oscillation by tuning the squeezing parameters. We also investigate geometric-phase oscillations for the case of a more general optical phenomenon where the squeezed state undergoes one-photon processes. It is shown that the geometric phase in this case exhibits additional intricate oscillations with small amplitudes, besides the principal oscillation. Such a sub-oscillation exhibits a beating-like behavior in time. The effects of geometric-phase oscillations are crucial in a wide range of wave interferences which are accompanied by rich physical phenomena such as Aharonov–Bohm oscillations, conductance fluctuations, antilocalizations, and nondissipative current flows.

Extending the Applicability of the ANI Deep Learning Molecular Potential to Sulfur and Halogens

2020 ◽  
Author(s):  
Christian Devereux ◽  
Justin Smith ◽  
Kate Davis ◽  
Kipton Barros ◽  
Roman Zubatyuk ◽  
...  
Keyword(s):  
Drug Development ◽  
Autonomous Vehicles ◽  
Potential Energy Surfaces ◽  
Organic Molecules ◽  
Chemical Elements ◽  
Molecular Potential ◽  
Wide Range ◽  
Energy Surfaces ◽  
New Applications ◽  
Physical Phenomena

<p>Machine learning (ML) methods have become powerful, predictive tools in a wide range of applications, such as facial recognition and autonomous vehicles. In the sciences, computational chemists and physicists have been using ML for the prediction of physical phenomena, such as atomistic potential energy surfaces and reaction pathways. Transferable ML potentials, such as ANI-1x, have been developed with the goal of accurately simulating organic molecules containing the chemical elements H, C, N, and O. Here we provide an extension of the ANI-1x model. The new model, dubbed ANI-2x, is trained to three additional chemical elements: S, F, and Cl. Additionally, ANI-2x underwent torsional refinement training to better predict molecular torsion profiles. These new features open a wide range of new applications within organic chemistry and drug development. These seven elements (H, C, N, O, F, Cl, S) make up ~90% of drug like molecules. To show that these additions do not sacrifice accuracy, we have tested this model across a range of organic molecules and applications, including the COMP6 benchmark, dihedral rotations, conformer scoring, and non-bonded interactions. ANI-2x is shown to accurately predict molecular energies compared to DFT with a ~10<sup>6</sup> factor speedup and a negligible slowdown compared to ANI-1x. The resulting model is a valuable tool for drug development that can potentially replace both quantum calculations and classical force fields for myriad applications.</p>

scholarly journals The XXL Survey

2018 ◽  
Vol 620 ◽  
pp. A7 ◽  
Author(s):  
V. Guglielmo ◽  
B. M. Poggianti ◽  
B. Vulcani ◽  
C. Adami ◽  
F. Gastaldello ◽  
...  
Keyword(s):  
Mass Function ◽  
Stellar Mass ◽  
X Ray ◽  
Field Versus ◽  
Final Sample ◽  
Wide Range ◽  
The Galaxy ◽  
Halo Masses ◽  
Stellar Masses ◽  
Physical Phenomena

Context. The fraction of galaxies bound in groups in the nearby Universe is high (50% at z ~ 0). Systematic studies of galaxy properties in groups are important in order to improve our understanding of the evolution of galaxies and of the physical phenomena occurring within this environment. Aims. We have built a complete spectrophotometric sample of galaxies within X-ray detected, optically spectroscopically confirmed groups and clusters (G&C), covering a wide range of halo masses at z ≤ 0.6. Methods. In the context of the XXL survey, we analyse a sample of 164 G&C in the XXL-North region (XXL-N), at z ≤ 0.6, with a wide range of virial masses (1.24 × 1013 ≤ M500,scal(M⊙) ≤ 6.63 × 1014) and X-ray luminosities ((2.27 × 1041 ≤ L500,scalXXL(erg s−1) ≤ 2.15 × 1044)). The G&C are X-ray selected and spectroscopically confirmed. We describe the membership assignment and the spectroscopic completeness analysis, and compute stellar masses. As a first scientific exploitation of the sample, we study the dependence of the galaxy stellar mass function (GSMF) on global environment. Results. We present a spectrophotometric characterisation of the G&C and their galaxies. The final sample contains 132 G&C, 22 111 field galaxies and 2225 G&C galaxies with r-band magnitude <20. Of the G&C, 95% have at least three spectroscopic members, and 70% at least ten. The shape of the GSMF seems not to depend on environment (field versus G&C) or X-ray luminosity (used as a proxy for the virial mass of the system). These results are confirmed by the study of the correlation between mean stellar mass of G&C members and L500,scalXXL. We release the spectrophotometric catalogue of galaxies with all the quantities computed in this work. Conclusions. As a first homogeneous census of galaxies within X-ray spectroscopically confirmed G&C at these redshifts, this sample will allow environmental studies of the evolution of galaxy properties.

scholarly journals Circular and transverse wave solutions of non-linear hyperbolic systems of equations

1968 ◽  
Vol 16 (2) ◽  
pp. 117-126
Author(s):  
Robin J. Waterston
Keyword(s):  
Hyperbolic Systems ◽  
Finite Elasticity ◽  
Linear Equations ◽  
Systems Of Equations ◽  
Transverse Waves ◽  
Hyperbolic Systems Of Equations ◽  
Wide Range ◽  
Non Linear ◽  
Physical Phenomena ◽  
Non Linear Equations

Circularly and transversely polarised (henceforth called circular and transverse) waves have been shown to occur as solutions of non-linear equations governing a wide range of physical phenomena, including finite elasticity (1), magnetohydrodynamics (2), and gyromagnetism (3), but only when the material properties of the medium are isotropic with respect to the direction of wave propagation. This paper is an attempt to unify and generalise these results.

DETECTION OF THE SPATIAL CURVATURE EFFECTS THROUGH PHYSICAL PHENOMENA: THE NONLINEAR COHERENT STATES APPROACH

2012 ◽  
Vol 09 (01) ◽  
pp. 1250009 ◽  
Author(s):  
A. MAHDIFAR ◽  
R. ROKNIZADEH ◽  
M. H. NADERI
Keyword(s):  
Hilbert Space ◽  
Geometric Phase ◽  
Coherent States ◽  
Transition Probability ◽  
Physical Space ◽  
Spatial Curvature ◽  
Curved Space ◽  
Curvature Effects ◽  
Projective Hilbert Space ◽  
Physical Phenomena

In this paper, by using the nonlinear coherent states approach, we find a relation between the geometric structure of the physical space and the geometry of the corresponding projective Hilbert space. To illustrate the approach, we explore the quantum transition probability and the geometric phase in the curved space.

Poisson flats in Euclidean spaces Part I: A finite number of random uniform flats

1969 ◽  
Vol 1 (2) ◽  
pp. 211-237 ◽  
Author(s):  
R. E. Miles
Keyword(s):  
Euclidean Space ◽  
Finite Number ◽  
Time Variation ◽  
Stochastic Independence ◽  
Geometrical Probability ◽  
Wide Range ◽  
Dimensional Distribution ◽  
The Common ◽  
High Degree ◽  
Physical Phenomena

This is the first part of a three part work, the common setting being Ed, Euclidean space of d dimensions. Many random physical phenomena, often in the form of structures, admit models which are assemblages of random s-flats in Ed. Indeed, taking s = 0, any n-sample from a d-dimensional distribution may of course be so regarded! For static phenomena generally 0 ≦ s < d ≦ 3, while 4 is to be substituted for 3 if time variation is allowed. By postulating a high degree of stochastic independence and uniformity, a variety of “simple” models is defined. However, their investigation poses problems in geometrical probability of a wide range of difficulty; the solutions of many of which are still far from complete.

Wavelet and multiscale methods for operator equations

Acta Numerica ◽  
1997 ◽  
Vol 6 ◽  
pp. 55-228 ◽  
Author(s):  
Wolfgang Dahmen
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Multiscale Methods ◽  
Parabolic Problems ◽  
Problem Size ◽  
Asymptotically Optimal ◽  
Wide Range ◽  
Intrinsic Complexity ◽  
Characteristic Features ◽  
Physical Phenomena

More than anything else, the increase of computing power seems to stimulate the greed for tackling ever larger problems involving large-scale numerical simulation. As a consequence, the need for understanding something like the intrinsic complexity of a problem occupies a more and more pivotal position. Moreover, computability often only becomes feasible if an algorithm can be found that is asymptotically optimal. This means that storage and the number of floating point operations needed to resolve the problem with desired accuracy remain proportional to the problem size when the resolution of the discretization is refined. A significant reduction of complexity is indeed often possible, when the underlying problem admits a continuous model in terms of differential or integral equations. The physical phenomena behind such a model usually exhibit characteristic features over a wide range of scales. Accordingly, the most successful numerical schemes exploit in one way or another the interaction of different scales of discretization. A very prominent representative is the multigrid methodology; see, for instance, Hackbusch (1985) and Bramble (1993). In a way it has caused a breakthrough in numerical analysis since, in an important range of cases, it does indeed provide asymptotically optimal schemes. For closely related multilevel techniques and a unified treatment of several variants, such as multiplicative or additive subspace correction methods, see Bramble, Pasciak and Xu (1990), Oswald (1994), Xu (1992), and Yserentant (1993). Although there remain many unresolved problems, multigrid or multilevel schemes in the classical framework of finite difference and finite element discretizations exhibit by now a comparatively clear profile. They are particularly powerful for elliptic and parabolic problems.

Simplified modellization of gear micropitting

2002 ◽  
Vol 216 (6) ◽  
pp. 291-302 ◽  
Author(s):  
F Antoine ◽  
J-M Besson
Keyword(s):  
Film Thickness ◽  
Thermochemical Treatment ◽  
Gear Train ◽  
Surface Finishing ◽  
Case Hardening ◽  
Reference Case ◽  
Oil Film ◽  
Epicyclic Gear ◽  
Wide Range ◽  
Physical Phenomena

This document gives a simplified method of calculating gear micropitting. The method has been developed by EUROCOPTER. The objective was to provide a model that took into consideration the maximum number of parameters in order to model the different physical phenomena, particularly: an oil-film thickness calculation taking the influence of pressure into consideration a simplified modellization of roughness an estimation of the plastification effect on the roughness overpressure at the contact surface taking into account the combined effects of roughness and oil-film thickness. The elaborated model is presented in an Excel file form. The application program is called APICS (approche du pitting par calculs simplifiés). In order to validate this model, this program has been applied to: An epicyclic gear train of a helicopter. Tests on discs as part of the ASETT European program. Discs are in hardened M50NiL Duplex (surface treatment: carburized and nitrided). Different kinds of surface finishing were proposed. The reference case of discs in 16NCD13 without thermochemical treatment has been also treated. FZG gear benchtests, also as part of the ASETT program. Gears have been manufactured in hardened M50NiL Duplex, with different kinds of surface finishing proposed. The results of the calculations express quite exactly the experimental facts observed on discs and gears for a wide range of studied cases, covering different materials, different kinds of case hardening and different kinds of surface finishing.

DYNAMICAL PHASE TRANSITION IN THE ISING MODEL ON A SCALE-FREE NETWORK

2005 ◽  
Vol 19 (32) ◽  
pp. 4769-4776 ◽  
Author(s):  
A. KRAWIECKI
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Ising Model ◽  
Tricritical Point ◽  
System Size ◽  
Critical Parameters ◽  
Dynamical Phase Transition ◽  
First Order ◽  
Dynamical Phase ◽  
Wide Range

Dynamical phase transition in the Ising model on a Barabási–Albert network under the influence of periodic magnetic field is studied using Monte-Carlo simulations. For a wide range of the system sizes N and the field frequencies, approximate phase borders between dynamically ordered and disordered phases are obtained on a plane h (field amplitude) versus T/Tc (temperature normalized to the static critical temperature without external field, Tc∝ ln N). On these borders, second- or first-order transitions occur, for parameter ranges separated by a tricritical point. For all frequencies of the magnetic field, position of the tricritical point is shifted toward higher values of T/Tc and lower values of h with increasing system size, i.e. the range of critical parameters corresponding to the first-order transition is broadened.

scholarly journals Electrophoretic deposition of coatings and bulk compacts using magnesium-doped aluminum oxide nanopowders

2021 ◽  
Vol 8 (2) ◽  
pp. 20218206
Author(s):  
E. G. Kalinina ◽  
D. S. Rusakova ◽  
E. Yu. Pikalova
Keyword(s):  
Aluminum Oxide ◽  
Electrophoretic Deposition ◽  
Spinel Phase ◽  
Bulk Sample ◽  
Linear Increase ◽  
Grain Structure ◽  
Average Grain Size ◽  
Wide Range ◽  
Small Cracks ◽  
Mg Content

The electrophoretic deposition (EPD) of coatings and bulk compacts in a wide range of thicknesses (from 23 to 1800 μm) from stable suspensions of a magnesium-doped aluminum oxide nanopowder with subsequent sintering of samples into dense ceramics was studied. The initial nanopowder was obtained by the method of electric explosion of an Al-Mg alloy wire with a Mg content of 1.3 wt. %. The study of the dispersion composition, kinetics of deaggregation under the ultrasonic treatment and zeta potential in the nanopowder-based suspensions was carried out. It was shown that a nearly linear increase in the deposited mass and thickness of EPD deposits occurred at a constant voltage of 20 V and an average deposition current of approximately 40 μA when the deposition time was varied from 1 to 180 min. Drying of the coatings with a thickness of less than 35 μm led to the formation of a net of small cracks, while drying of the bulk compacts with a thickness of more than 1 mm occurred without cracking. The ceramic bulk sample with a thickness of 1.2 mm and the density of 98.7% TD was successfully obtained by sintering at 1650 °C for 4 h. It was characterized by a dense grain structure with an average grain size of 5 μm and the presence of a small number of closed pores less than 1 μm in size. Sintering of ceramics was revealed to be accompanied by the formation of a MgAl2O4 crystalline spinel phase, localized mainly at grain boundaries.

scholarly journals DNA-assembled superconducting 3D nanoscale architectures

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Lior Shani ◽  
Aaron N. Michelson ◽  
Brian Minevich ◽  
Yafit Fleger ◽  
Michael Stern ◽  
...  
Keyword(s):  
Self Assembly ◽  
Quantum Interference ◽  
Three Dimensional ◽  
Electrical Characterization ◽  
Field Vector ◽  
Parametric Amplifiers ◽  
Liquid Environment ◽  
Superconducting Quantum Interference ◽  
Wide Range ◽  
Physical Phenomena

Abstract Studies of nanoscale superconducting structures have revealed various physical phenomena and led to the development of a wide range of applications. Most of these studies concentrated on one- and two-dimensional structures due to the lack of approaches for creation of fully engineered three-dimensional (3D) nanostructures. Here, we present a ‘bottom-up’ method to create 3D superconducting nanostructures with prescribed multiscale organization using DNA-based self-assembly methods. We assemble 3D DNA superlattices from octahedral DNA frames with incorporated nanoparticles, through connecting frames at their vertices, which result in cubic superlattices with a 48 nm unit cell. The superconductive superlattice is formed by converting a DNA superlattice first into highly-structured 3D silica scaffold, to turn it from a soft and liquid-environment dependent macromolecular construction into a solid structure, following by its coating with superconducting niobium (Nb). Through low-temperature electrical characterization we demonstrate that this process creates 3D arrays of Josephson junctions. This approach may be utilized in development of a variety of applications such as 3D Superconducting Quantum interference Devices (SQUIDs) for measurement of the magnetic field vector, highly sensitive Superconducting Quantum Interference Filters (SQIFs), and parametric amplifiers for quantum information systems.

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