scholarly journals Quantum Steering in Two- and Three-Mode ??-Symmetric Systems

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2201
Author(s):  
Vinh Le Duc ◽  
Joanna K. Kalaga ◽  
Wiesław Leoński ◽  
Mateusz Nowotarski ◽  
Konrad Gruszka ◽  
...  
Keyword(s):  
Linear Chain ◽  
Single Mode ◽  
Generation Process ◽  
System Parameters ◽  
Quantum Steering ◽  
Coupling Strengths ◽  
Linear Interactions ◽  
Symmetric Systems

We consider two PT-symmetric models, consisting of two or three single-mode cavities. In both models, the cavities are coupled to each other by linear interactions, forming a linear chain. Additionally, the first and last of such cavities interact with an environment. Since the models are PT-symmetric, they are described by non-Hermitian Hamiltonians that, for a specific range of system parameters, possess real eigenvalues. We show that in the models considered in the article, the steering generation process strongly depends on the coupling strengths and rates of the gains/losses in energy. Moreover, we find the values of parameters describing the system for which the steering appears.

Unstable Vibrations of a Wind Turbine Tower With Two Blades

2012 ◽  
Author(s):  
Takashi Ikeda ◽  
Yuji Harata ◽  
Yukio Ishida
Keyword(s):  
Wind Turbine ◽  
Equations Of Motion ◽  
Single Mode ◽  
Single Frequency ◽  
Dual Mode ◽  
Response Curves ◽  
Moments Of Inertia ◽  
System Parameters ◽  
Wind Turbine Tower ◽  
The Asymmetry

Unstable vibrations of a two-blade wind turbine tower are theoretically investigated. The theoretical model is a five-degree-of-freedom (5DOF) system, however, the equations of motion are derived separately for 3DOF subsystem (I) and 2DOF subsystem (II). Parametric excitation due to the asymmetry of the moments of inertia of the blade rotor is included only in subsystem (I). Frequency equations are derived and natural frequency diagrams are calculated to clearly demonstrate both the rotational speeds where unstable regions appear and which type of unstable vibrations may occur. It is found that at most, five unstable regions may appear depending on the values of the system parameters in subsystem (I). Two types of unstable vibrations may occur; single mode including a single frequency and dual mode including two frequencies. The influences of the asymmetry of moments of inertia, tower rigidity, and installation position of the blade rotor on the response of the system are also theoretically investigated. Van der Pol’s method is applied to determine the expressions for the response curves. The influences of the blade rotor unbalances on the translational, inclinational and torsional vibrations of the tower are shown. It is found that the amplitudes of the response curves corresponding to single and dual mode are infinite and finite at their boundaries, respectively. The validity of the theoretical analysis is confirmed by numerical simulations.

Relativistic motion on Gaussian quantum steering for two-mode localized Gaussian states

2021 ◽  
Author(s):  
Gong Xiao-long ◽  
Cao Shuo ◽  
Yue Fang ◽  
Liu Tong-Hua
Keyword(s):  
Single Mode ◽  
Quantum Systems ◽  
Unruh Effect ◽  
Gaussian States ◽  
The Earth ◽  
Single Mode Approximation ◽  
Quantum Steering ◽  
The One ◽  
Interesting Behavior ◽  
Monotonically Decrease

Abstract Realistic quantum systems always exhibit gravitational and relativistic features. In this paper, we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states, instead of the traditional single-mode approximation method in the relativistic setting. We find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of acceleration. Meanwhile, our results also reveal the interesting behavior of the Gaussian steering asymmetry, which increases for a specific range of accelerated parameter and then gradually approaches to a finite value. Such findings is well consistent and explained by the well-known Unruh effect, which could significantly destroy the one-side Gaussian quantum steering. Finally, our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites, since the effects of acceleration is equal to the effects of gravity according to the equivalence principle.

scholarly journals Asymptotic Entanglement Sudden Death in Two Atoms with Dipole–Dipole and Ising Interactions Coupled to a Radiation Field at Non-Zero Detuning

Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 629
Author(s):  
Gehad Sadiek ◽  
Wiam Al-Dress ◽  
Salwa Shaglel ◽  
Hala Elhag
Keyword(s):  
Asymptotic Behavior ◽  
Sudden Death ◽  
Radiation Field ◽  
Quantum Correlation ◽  
Bell State ◽  
Single Mode ◽  
Mean Value ◽  
Entanglement Sudden Death ◽  
Initial State ◽  
System Parameters

We investigate the time evolution and asymptotic behavior of a system of two two-level atoms (qubits) interacting off-resonance with a single mode radiation field. The two atoms are coupled to each other through dipole--dipole as well as Ising interactions. An exact analytic solution for the system dynamics that spans the entire phase space is provided. We focus on initial states that cause the system to evolve to entanglement sudden death (ESD) between the two atoms. We find that combining the Ising and dipole--dipole interactions is very powerful in controlling the entanglement dynamics and ESD compared with either one of them separately. Their effects on eliminating ESD may add up constructively or destructively depending on the type of Ising interaction (Ferromagnetic or anti-Ferromagnetic), the detuning parameter value, and the initial state of the system. The asymptotic behavior of the ESD is found to depend substantially on the initial state of the system, where ESD can be entirely eliminated by tuning the system parameters except in the case of an initial correlated Bell state. Interestingly, the entanglement, atomic population and quantum correlation between the two atoms and the field synchronize and reach asymptotically quasi-steady dynamic states. Each one of them ends up as a continuous irregular oscillation, where the collapse periods vanish, with a limited amplitude and an approximately constant mean value that depend on the initial state and the system parameters choice. This indicates an asymptotic continuous exchange of energy (and strong quantum correlation) between the atoms and the field takes place, accompanied by diminished ESD for these chosen setups of the system. This system can be realized in spin states of quantum dots or Rydberg atoms in optical cavities, and superconducting or hybrid qubits in linear resonators.

scholarly journals Generation of general system parameters for Rainbow signature scheme

2021 ◽  
pp. 83-87
Author(s):  
Yelyzaveta Ostrianska ◽  
Olha Mirzoieva
Keyword(s):  
Algebraic Structure ◽  
General System ◽  
Generation Process ◽  
Signature Scheme ◽  
Electronic Signature ◽  
System Parameters ◽  
Signature Generation ◽  
Large Size ◽  
Public Keys ◽  
Main Disadvantage

The paper considers the description of electronic signature scheme Rainbow, which is based on multivariate transformations. It is a generalization of the UOV structure, which provides efficient parameterization due to the additional algebraic structure. The article provides an initial analysis of known attacks on the ES Rainbow scheme. Also, algorithms for generating general system parameters for 384 and 512 security bits were developed and the results are presented in this paper. The study found that the Rainbow signature generation process consists of simple operations of linear algebra, such as multiplying matrix vectors and solving linear systems over small finite fields. Another advantage of Rainbow is that this scheme offers very small signatures of only a few hundred bits. But the main disadvantage of Rainbow is the large size of public keys.

scholarly journals Effect of fiber and solenoid variation parameters on the elements of a corrector PID for electromagnetic fiber squeezer based polarization controller

2020 ◽  
Vol 10 (3) ◽  
pp. 2441 ◽  
Author(s):  
Abdallah Zahidi ◽  
Amrane Said ◽  
Nawfel Azami ◽  
Naoual Nasser
Keyword(s):  
Detection System ◽  
Light Output ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Open Loop ◽  
Polarization Controller ◽  
Heterodyne Detection ◽  
System Parameters ◽  
Stability Performance ◽  
The Stability

Controlling the polarization of the light output from single-mode fiber systems is very important for connecting it to polarization-dependent integrated optical circuits, while applications using a heterodyne detection system. Polarization controller using fiber squeezer is attractive for a low-loss, low-penalty coherent optical fiber trunk system. However, for polarization controllers using electromagnetic fiber squeezer, the stability problem due to the saturation of their magnetic circuit must be studied. In fact, in their conventional configuration, open-loop stability affects performance and limits applications. First at all, this effect has been analyzed and a feedback circuit with correctors has been proposed to improve stability performance. Then a simulation study is proposed to examine the influence of the system parameters on the corrector constants. The results of the simulation show that if the system parameters change the constants Kp, Ki and Kd of the PID corrector must be adjusted to keep an optimized dynamic response.

scholarly journals Entropic nonclassicality and quantum non-Gaussianity tests via beam splitting

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jiyong Park ◽  
Jaehak Lee ◽  
Hyunchul Nha
Keyword(s):  
Beam Splitter ◽  
Single Mode ◽  
Quantum States ◽  
Homodyne Detection ◽  
Beam Splitting ◽  
Epr Paradox ◽  
Classical State ◽  
Splitting Operation ◽  
Quantum Steering ◽  
Phase Randomization

AbstractWe propose entropic nonclassicality criteria for quantum states of light that can be readily tested using homodyne detection with beam splitting operation. Our method draws on the fact that the entropy of quadrature distributions for a classical state is non-increasing under an arbitrary loss channel. We show that our test is strictly stronger than the variance-based squeezing condition and that it can also be extended to detect quantum non-Gaussianity in conjunction with phase randomization. Furthermore, we address how our criteria can be used to identify single-mode resource states to generate two-mode states demonstrating EPR paradox, i.e., quantum steering, via beam-splitter setting.

A Singular Perturbation Analysis of Eigenvalue Veering and Mode Localization in Perturbed Linear Chain and Cyclic Systems

1991 ◽  
Author(s):  
G. S. Happawana ◽  
A. K. Bajaj ◽  
O. D. I. Nwokah
Keyword(s):  
Singular Perturbation ◽  
Asymptotic Expansions ◽  
Linear Chain ◽  
Mode Localization ◽  
Singular Perturbation Analysis ◽  
Weakly Coupled ◽  
Component Systems ◽  
Cyclic Symmetric ◽  
Symmetric Systems ◽  
Uniform Asymptotic Expansions

Abstract An investigation into the eigenvalue loci veering and mode localization phenomenon is presented for mistuned structural systems. Examples from both, the weakly coupled uniaxial component systems and the cyclic symmetric systems, are considered. The analysis is based on singular perturbation techniques. It is shown that uniform asymptotic expansions for the eigenvalues and eigenvectors can be constructed in terms of the mistuning parameters, and these solutions are in excellent agreement with the exact solutions. The asymptotic expansions are then used to clearly show how the singular behavior in the eigenfunctions or modeshapes leads to mode localization.

ENTANGLEMENT OF A SINGLE-MODE CAVITY QED OF A RAMAN INTERACTION

2007 ◽  
Vol 05 (01n02) ◽  
pp. 105-110 ◽  
Author(s):  
M. ABDEL-ATY ◽  
F. AL-SHOWAIKH ◽  
S. S. HASSAN
Keyword(s):  
Cavity Qed ◽  
Energy Levels ◽  
Single Mode ◽  
Entanglement Measure ◽  
Cavity Field ◽  
System Parameters ◽  
Raman Process ◽  
Raman Interaction ◽  
Single Mode Cavity

We investigate the entanglement of a degenerate Raman process involving two degenerate Rydberg energy levels of an atom interacting with a single-mode cavity field. We use the concurrence as an entanglement measure and show that long living entanglement can be obtained for certain choices of the system parameters.

Sign in / Sign up

Export Citation Format

Share Document