scholarly journals Quantum Features of Atom–Field Systems in the Framework of Deformed Fields

2021 ◽  
Vol 11 (1) ◽  
pp. 408
Author(s):  
Sayed Abdel-Khalek ◽  
Kamal Berrada ◽  
Abeer S. Altowyan
Keyword(s):  
Dynamical Behavior ◽  
Quantum Systems ◽  
Physical Parameters ◽  
Large Set ◽  
Nonlocal Correlation ◽  
Nonclassical Properties ◽  
Laser Systems ◽  
Physical Importance ◽  
Schrodinger Cat State ◽  
Spin Coherent States

We propose a new kind of Schrödinger cat state introduced as a superposition of spin coherent states in the framework of noncommutative spaces. We analyze the nonclassical features for these noncommutative deformed states in terms of the main physical parameters. The physical importance of deformed states is that they provide a convenient description of a large set of laser systems. As an application, we develop the Jaynes–Cummings model by considering the interaction among atoms and cat state fields associated to deformed spin algebras. In this context, we show the dynamical behavior of the nonlocal correlation and nonclassical properties in these quantum systems.

Cluster state quantum computation for many-level systems

2007 ◽  
Vol 7 (3) ◽  
pp. 184-208
Author(s):  
W. Hall
Keyword(s):  
Quantum Computation ◽  
Degrees Of Freedom ◽  
Cluster State ◽  
Quantum Systems ◽  
Explicit Description ◽  
State Model ◽  
Mutually Unbiased Bases ◽  
Large Set ◽  
Adaptive Computation ◽  
Complete Framework

The cluster state model for quantum computation [Phys. Rev. Lett. \textbf{86}, 5188] outlines a scheme that allows one to use measurement on a large set of entangled quantum systems in what is known as a cluster state to undertake quantum computations. The model itself and many works dedicated to it involve using entangled qubits. In this paper we consider the issue of using entangled qudits instead. We present a complete framework for cluster state quantum computation using qudits, which not only contains the features of the original qubit model but also contains the new idea of adaptive computation: via a change in the classical computation that helps to correct the errors that are inherent in the model, the implemented quantum computation can be changed. This feature arises through the extra degrees of freedom that appear when using qudits. Finally, for prime dimensions, we give a very explicit description of the model, making use of mutually unbiased bases.

scholarly journals The Dynamical Behavior of a Rigid Body Relative Equilibrium Position

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
T. S. Amer
Keyword(s):  
Rigid Body ◽  
Degrees Of Freedom ◽  
Numerical Solutions ◽  
Equations Of Motion ◽  
Relative Equilibrium ◽  
Dynamical Behavior ◽  
Vertical Plane ◽  
The Body ◽  
Physical Parameters ◽  
Pendulum Model

In this paper, we will focus on the dynamical behavior of a rigid body suspended on an elastic spring as a pendulum model with three degrees of freedom. It is assumed that the body moves in a rotating vertical plane uniformly with an arbitrary angular velocity. The relative periodic motions of this model are considered. The governing equations of motion are obtained using Lagrange’s equations and represent a nonlinear system of second-order differential equations that can be solved in terms of generalized coordinates. The numerical solutions are investigated using the fourth-order Runge-Kutta algorithms through Matlab packages. These solutions are represented graphically in order to describe and discuss the behavior of the body at any instant for different values of the physical parameters of the body. The obtained results have been discussed and compared with some previous published works. Some concluding remarks have been presented at the end of this work. The importance of this work is due to its numerous applications in life such as the vibrations that occur in buildings and structures.

scholarly journals Equilibrium Configurations of the Noncircular Cross-Section Elastic Rod Model with the Elliptic KB Method

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yongzhao Wang ◽  
Qichang Zhang ◽  
Wei Wang
Keyword(s):  
Cross Section ◽  
Dynamical Behavior ◽  
Elliptic Functions ◽  
Physical Parameters ◽  
Valuable Insight ◽  
Elastic Rod ◽  
Noncircular Cross Section ◽  
Equilibrium Configurations ◽  
Rational Expressions ◽  
Elastic Rod Model

The mechanical deformation of DNA is very important in many biological processes. In this paper, we consider the reduced Kirchhoff equations of the noncircular cross-section elastic rod characterized by the inequality of the bending rigidities. One family of exact solutions is obtained in terms of rational expressions for classical Jacobi elliptic functions. The present solutions allow the investigation of the dynamical behavior of the system in response to changes in physical parameters that concern asymmetry. The effects of the factor on the DNA conformation are discussed. A qualitative analysis is also conducted to provide valuable insight into the topological configuration of DNA segments.

An Overview on a Nonideal System With Three and a Half Degrees of Freedom

2005 ◽  
Author(s):  
Karen de Lolo Guilherme ◽  
Jose´ Manoel Balthazar ◽  
Paulo Roberto Gardel Kurka ◽  
Masayoshi Tsuchida
Keyword(s):  
Degrees Of Freedom ◽  
Averaging Method ◽  
Dynamical Behavior ◽  
Mathematical Formulation ◽  
Rotation Frequency ◽  
Steady State Solution ◽  
Dc Motor ◽  
Physical Parameters ◽  
Phase Coordinates ◽  
Limited Power

The present paper studies a system comprised of two blocks connected by springs and dampers, and a DC motor with limited power supply fixed on a block, characterizing a non-ideal problem. This DC motor exciting the system causes interactions between the motor and the structure supporting it. Because of that, the non-ideal mathematical formulation of the problem has one and a half extra degree of freedom than the ideal one. A suitable choice of physical parameters leads to internal resonance conditions, that is, its natural frequencies are multiple of each other, by a known integer quantity. The purpose here is to study the dynamic behavior of the system using an analytical method based on perturbation techniques. The literature shows that the averaging method is the more flexible method concerning non-ideal problems. Summarizing, an steady state solution in amplitude and phase coordinates was obtained with averaging method showing the dependence of the structure amplitudes with the rotation frequency of the motor. Moreover, this solution shows that on of the amplitude coordinates has influence in the determination of the stationary rotation frequency. The analytical solution obtained shows the presence of the rotation frequency in expressions representing the oscillations of the structure, and the presence of amplitude coordinates in expressions describing the dynamic motion of the DC motor. These characteristics show the influence not only of the motor on structure but also of the response of the structure on dynamical behavior of the motor.

Entropy squeezing, nonlocal correlation and purification properties of two-trap ion interaction with laser field in the presence of Stark shift effect

2019 ◽  
Vol 33 (12) ◽  
pp. 1950118
Author(s):  
Yas Al-Hadeethi ◽  
Bahaaudin M. Raffah ◽  
Nawal Almalky ◽  
E. M. Khalil
Keyword(s):  
Laser Field ◽  
Entanglement Entropy ◽  
Dynamical Behavior ◽  
Stark Shift ◽  
Entanglement Sudden Death ◽  
Entropy Squeezing ◽  
Trapped Ion ◽  
Nonlocal Correlation ◽  
Initial States ◽  
Shift Effect

In this paper, the interaction between two trap ions with laser beam and electromagnetic field containing the Stark shift terms has been investigated. The analytical solution for the differential equations which describes the system Hamiltonian is obtained. The dynamical behavior for the entanglement, entropy squeezing and purity of system are discussed. Some important physical characteristics such as revivals and collapses for the occupation of the trapped ion, entanglement sudden death (birth) and single trapped ion entropy squeezing are discussed. In addition, the influence of Lamb–Dicke parameter and the initial states on the evolution of the entanglement, linear entropy are studied. Finally, some remarks about the obtained results are given briefly.

Corrigendum 1 (published 19 Sep 2018) and Corrigendum 2 (published 11 Dec 2018) to: Wildland fires behaviour: wind effect versus Byram’s convective number and consequences upon the regime of propagation

2018 ◽  
Vol 27 (12) ◽  
pp. 857
Author(s):  
D. Morvan ◽  
N. Frangieh
Keyword(s):  
Wind Velocity ◽  
Wildland Fire ◽  
Short Note ◽  
Short Paper ◽  
Speed Ratio ◽  
Wind Effect ◽  
Physical Parameters ◽  
Large Set ◽  
Wildland Fires ◽  
The Relationship

With fuel moisture content and slope, wind velocity (UW) is one of the major physical parameters that most affects the behaviour of wildland fires. The aim of this short paper was to revisit the relationship between the rate of spread (ROS) and the wind velocity, through the role played by the two forces governing the trajectory of the flame front and the plume, i.e. the buoyancy of the plume and the inertia due to wind. A large set of experimental data (at field and laboratory scale) from the literature was analysed, by introducing the ratio between these two forces, namely Byram's convective number NC and considering the relationship between the fire ROS/wind speed ratio and Byram's number. This short note was also an opportunity to make a point on particular issues, such as the existence of two regimes of propagation of surface fires (wind-driven fire vs plume-dominated fire), the relative importance of the two modes of heat transfer (by convection and radiation) on the propagation of a fire front, and others scientific debates animating the wildland fire community.

scholarly journals Wildland fires behaviour: wind effect versus Byram’s convective number and consequences upon the regime of propagation

2018 ◽  
Vol 27 (9) ◽  
pp. 636 ◽  
Author(s):  
D. Morvan ◽  
N. Frangieh
Keyword(s):  
Wind Velocity ◽  
Wildland Fire ◽  
Short Note ◽  
Short Paper ◽  
Speed Ratio ◽  
Wind Effect ◽  
Physical Parameters ◽  
Large Set ◽  
Wildland Fires ◽  
The Relationship

With fuel moisture content and slope, wind velocity (UW) is one of the major physical parameters that most affects the behaviour of wildland fires. The aim of this short paper was to revisit the relationship between the rate of spread (ROS) and the wind velocity, through the role played by the two forces governing the trajectory of the flame front and the plume, i.e. the buoyancy of the plume and the inertia due to wind. A large set of experimental data (at field and laboratory scale) from the literature was analysed, by introducing the ratio between these two forces, namely Byram’s convective number NC and considering the relationship between the fire ROS/wind speed ratio and Byram’s number. This short note was also an opportunity to make a point on particular issues, such as the existence of two regimes of propagation of surface fires (wind-driven fire vs plume-dominated fire), the relative importance of the two modes of heat transfer (by convection and radiation) on the propagation of a fire front, and others scientific debates animating the wildland fire community.

AN EXPERIMENTAL APPLICATION OF THE ANTICONTROL OF HOPF BIFURCATIONS

2001 ◽  
Vol 11 (07) ◽  
pp. 1977-1987 ◽  
Author(s):  
DIEGO M. ALONSO ◽  
EDUARDO E. PAOLINI ◽  
JORGE L. MOIOLA
Keyword(s):  
Dynamical Behavior ◽  
Oscillatory Behavior ◽  
Numerical Continuation ◽  
Physical Parameters ◽  
Hopf Bifurcations ◽  
Control Laws ◽  
Bifurcation Phenomena ◽  
Local Approximations ◽  
The Subject ◽  
Active Research

The control of nonlinear systems exhibiting bifurcation phenomena has been the subject of active research in recent years. Contrary to regulation or tracking objectives common in classic control, in some applications it is desirable to achieve an oscillatory behavior. Towards this end, bifurcation control aims at designing a controller to modify the bifurcative dynamical behavior of a complex nonlinear system. Among the available methods, the so-called "anti-control" of Hopf bifurcations is one approach to design limit cycles in a system via feedback control. In this paper, this technique is applied to obtain oscillations of prescribed amplitude in a simple mechanical system: an underactuated pendulum. Two different nonlinear control laws are described and analyzed. Both are designed to modify the coefficients of the linearization matrix of the system via feedback. The first law modifies those coefficients that correspond to the physical parameters, whereas the second one changes some null coefficients of the linearization matrix. The latter results in a simpler controller that requires the measurement of only one state of the system. The dependence of the amplitudes as function of the feedback gains is obtained analytically by means of local approximations, and over a larger range by numerical continuation of the periodic solutions. Theoretical results are contrasted by both computer simulations and experimental results.

Numerical Simulation of Cloud–Clear Air Interfacial Mixing: Effects on Cloud Microphysics

2006 ◽  
Vol 63 (12) ◽  
pp. 3204-3225 ◽  
Author(s):  
Miroslaw Andrejczuk ◽  
Wojciech W. Grabowski ◽  
Szymon P. Malinowski ◽  
Piotr K. Smolarkiewicz
Keyword(s):  
Numerical Simulation ◽  
Cloud Microphysics ◽  
Physical Parameters ◽  
Large Set ◽  
Low Resolution ◽  
Cloud Droplets ◽  
Important Conclusion ◽  
Cloud Models ◽  
The Mean ◽  
Interfacial Mixing

This paper extends the previously published numerical study of Andrejczuk et al. on microscale cloud–clear air mixing. Herein, the primary interest is on microphysical transformations. First, a convergence study is performed—with well-resolved direct numerical simulation of the interfacial mixing in the limit—to optimize the design of a large series of simulations with varying physical parameters. The principal result is that all conclusions drawn from earlier low-resolution (Δx = 10−2 m) simulations are corroborated by the high-resolution (Δx = 0.25 × 10−2 m) calculations, including the development of turbulent kinetic energy (TKE) and the evolution of microphysical properties. This justifies the use of low resolution in a large set of sensitivity simulations, where microphysical transformations are investigated in response to variations of the initial volume fraction of cloudy air, TKE input, liquid water mixing ratio in cloudy filaments, relative humidity (RH) of clear air, and size of cloud droplets. The simulations demonstrate that regardless of the initial conditions the evolutions of the number of cloud droplets and the mean volume radius follow a universal path dictated by the TKE input, RH of clear air filaments, and the mean size of cloud droplets. The resulting evolution path only weakly depends on the progress of the homogenization. This is an important conclusion because it implies that a relatively simple rule can be developed for representing the droplet-spectrum evolution in cloud models that apply parameterized microphysics. For the low-TKE input, when most of the TKE is generated by droplet evaporation during mixing and homogenization, an inhomogeneous scenario is observed with approximately equal changes in the dimensionless droplet number and mean volume radius cubed. Consistent with elementary scale analysis, higher-TKE inputs, higher RH of cloud-free filaments, and larger cloud droplets enhance the homogeneity of mixing. These results are discussed in the context of observations of entrainment and mixing in natural clouds.

scholarly journals Macroscopic Limit of Quantum Systems

Universe ◽  
2021 ◽  
Vol 7 (9) ◽  
pp. 315
Author(s):  
Janos Polonyi
Keyword(s):  
Quantum Systems ◽  
Classical Trajectory ◽  
Time Dependent ◽  
Large Set ◽  
Measuring Apparatus ◽  
Technical Device ◽  
Expectation Value ◽  
Avogadro’S Number ◽  
The Central Limit Theorem ◽  
Quantum Version

Classical physics is approached from quantum mechanics in the macroscopic limit. The technical device to achieve this goal is the quantum version of the central limit theorem, derived for an observable at a given time and for the time-dependent expectation value of the coordinate. The emergence of the classical trajectory can be followed for the average of an observable over a large set of independent microscopical systems, and the deterministic classical laws can be recovered in all practical purposes, owing to the largeness of Avogadro’s number. This result refers to the observed system without considering the measuring apparatus. The emergence of a classical trajectory is followed qualitatively in Wilson’s cloud chamber.

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