Polarization switching （PS） dynamics and synchronization performances of two mutually coupled vertical-cavity surface-emitting lasers （VCSELs） are studied theoretically in this paper. A group of dimensionless rate...Polarization switching （PS） dynamics and synchronization performances of two mutually coupled vertical-cavity surface-emitting lasers （VCSELs） are studied theoretically in this paper. A group of dimensionless rate equations is derived to describe our model. While analysing the PS characteristics, we focus on the effects of coupling rate and frequency detuning regarding different mutual injection types. The results indicate that the x-mode injection defers the occurrence of PS, while the y-mode injection leads the PS to occur at a lower current. Strong enough polarization-selective injection can suppress the PS. Moreover, if frequency detuning is considered, the effects of polarization-selective mutual injection will be weakened. To evaluate the synchronization performance, the correlation coefficients and output dynamics of VCSELs with both pure mode and mixed mode polarizations are given. It is found that performance of complete synchronization is sensitive to the frequency mismatch but it is little affected by mixed mode polarizations, which is opposite to the case of injection-locking synchronization.展开更多
This paper addresses the control law design for synchronization of two different chaotic oscillators with mutually Lipschitz nonlinearities. For analysis of the properties of two different nonlinearities, an advanced ...This paper addresses the control law design for synchronization of two different chaotic oscillators with mutually Lipschitz nonlinearities. For analysis of the properties of two different nonlinearities, an advanced mutually Lipschitz condition is proposed. This mutually Lipschitz condition is more general than the traditional Lipschitz condition. Unlike the latter, it can be used for the design of a feedback controller for synchronization of chaotic oscillators of different dynamics. It is shown that any two different Lipschitz nonlinearities always satisfy the mutually Lipschitz condition. Applying the mutually Lipschitz condition, a quadratic Lyapunov function and uniformly ultimately bounded stability, easily designable and implementable robust control strategies utilizing algebraic Riccati equation and linear matrix inequalities, are derived for synchronization of two distinct chaotic oscillators. Furthermore, a novel adaptive control scheme for mutually Lipschitz chaotic systems is established by addressing the issue of adaptive cancellation of unknown mismatch between the dynamics of different chaotic systems. The proposed control technique is numerically tested for synchronization of two different chaotic Chua＇s circuits and for obtaining identical behavior between the modified Chua＇s circuit and the R6ssler system.展开更多
Understanding the cause of the synchronization of population evolution is an important issue for ecologicalimprovement.Here we present a Lotka-Volterra-type model driven by two correlated environmental noises and show...Understanding the cause of the synchronization of population evolution is an important issue for ecologicalimprovement.Here we present a Lotka-Volterra-type model driven by two correlated environmental noises and show,via theoretical analysis and direct simulation,that noise correlation can induce a synchronization of the mutualists.Thetime series of mutual species exhibit a chaotic-like fluctuation,which is independent of the noise correlation,however,the chaotic fluctuation of mutual species ratio decreases with the noise correlation.A quantitative parameter defined forcharacterizing chaotic fluctuation provides a good approach to measure when the complete synchronization happens.展开更多
This paper studies the problem of isochronal synchronization of chaotic systems with time-delayed mutual coupling. Based on the invariance principle of differential equations, an adaptive feedback scheme is proposed f...This paper studies the problem of isochronal synchronization of chaotic systems with time-delayed mutual coupling. Based on the invariance principle of differential equations, an adaptive feedback scheme is proposed for the stability of isochronal synchronization between two identical chaotic systems. Unlike the usual linear feedback, the variable feedback strength is automatically adapted to isochronally synchronize two identical chaotic systems with delay-coupled, so this scheme is analytical, and simple to implement in practice. Simulation results show that the isochronal synchronization behavior is determined by time delay.展开更多
We investigate the transient spontaneous quantum synchronization between two qubits interacting with a common non-Markovian environment based on a collision model.We are mainly interested in the effect of non-Markovia...We investigate the transient spontaneous quantum synchronization between two qubits interacting with a common non-Markovian environment based on a collision model.We are mainly interested in the effect of non-Markovianity on the synchronization between two qubits.We find that the non-Markovianity always delay the anti-synchronization and decrease the parameter region where the qubits get anti-synchronized.Meanwhile,we define V to characterize the visibility of synchronization and show that there is an apparent link among V,entanglement and quantum mutual information whether in the Markovian or non-Markovian regimes when the environment is in the vacuum state.Moreover,with the increase of temperature,the parameter region of the emergence of anti-synchronization and the time to get anti-synchronized in the non-Markovian regime gradually approaches that in the Markovian regime.The high temperature decreases the parameter region of the emergence of anti-synchronization in both Markovian and non-Markovian regimes,and breaks the connection among V,entanglement and quantum mutual information.展开更多
We perform an analysis of brain-neuromuscular synchronization and coupling strength in muscular dystrophy before and after NPT treatment. In order to estimate with accuracy the level of brain synchronization, we intro...We perform an analysis of brain-neuromuscular synchronization and coupling strength in muscular dystrophy before and after NPT treatment. In order to estimate with accuracy the level of brain synchronization, we introduce and use the method of the cross GMI that was elaborated by Pompe. The finality is to account for the nonlinear chaotic dynamic contributions that regulate the dynamics. We find that this method is excellent and it may be applied in such case of sEMG and EEG study as well as at a general neurological level. By it we arrive to quantify the coupling strength and synchronization first between two muscular sections (left and right trapezes) and after between Brain activity, as recorded by the EEG, and the trapezes. We compare the results before and after the NPT treatment and we find that the improvement obtained following such treatment is very consistent. We have now in progress other studies relating in particular the application of such new methodologies to other more serious pathologies as the HSP (Hereditary Spastic Paraplegia).展开更多
Coupled oscillators are common in many scientific areas,such as optics,communications,engi-neering,biology,etc.The synchronization of oscillators has important practical applications.This letter focuses on synchroniza...Coupled oscillators are common in many scientific areas,such as optics,communications,engi-neering,biology,etc.The synchronization of oscillators has important practical applications.This letter focuses on synchronization of coupled hyperchaotic oscillators,which exists in natureand in laboratory and is very important.展开更多
Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS （electric power sys...Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS （electric power system） mode. Discussion will focus on different models obtained from data synchronized measurements for operational and automatic emergency control without EPS being totally controlled. According to the proposed technology, the generator＇s output power restrictions are determined in real-time by the terms a static stability using the generators＇ mode model as a multipole with connection nodes of generators＇ electromotive forces （the matrix of SMA （self and mutual admittances） of electromotive forces of generators）. Potential applications of the technology are distribution network with the main substation and generators of commensurable capacity, and transmission network with large power plants （generators） distributed into the network. The one-level control system for all of generators with defining the generator＇s power limits relative to the main substation is implemented in the first case. In the second case, the two-level control system is brought in, based on the separation of large and small generation motion. The results of the method and technology efficiency verification are shown in the paper, by both computer simulations of the power system modes and its physical model.展开更多
The synchronization of nonlinear systems has been demonstrated in several natural systems,which not only enhances the performance of spin torque oscillators(STOs)but also enables the modification of STOs for new compu...The synchronization of nonlinear systems has been demonstrated in several natural systems,which not only enhances the performance of spin torque oscillators(STOs)but also enables the modification of STOs for new computing architectures.This paper reviews recent advances in the mutual synchronization,forced synchronization,and noise synchronization of STOs from both theoretical and experimental perspectives.The main types of synchronization discussed include spin wave synchronization,dipolar field synchronization,electrical connection synchronization,and injection locking.After introducing the theoretical and experimental progress in these fields,we highlight the importance of synchronization for practical applications in both microwave devices and neuromorphic computing.The significance of these studies for understanding and applying STO synchronization is emphasized,and we offer our perspective on current research,suggesting directions for future studies.展开更多
Two vertical-cavity surface-emitting lasers（VCSELs） are mutually coupled through a partially transparent mirror （PTM） placed in the pathway. The PTM plays the role of external mirror, which controls the feedback s...Two vertical-cavity surface-emitting lasers（VCSELs） are mutually coupled through a partially transparent mirror （PTM） placed in the pathway. The PTM plays the role of external mirror, which controls the feedback strength and coupling strength. We numerically simulate this system by establishing a visible SIMULINK model. The results demonstrate that the anticipation synchronization is achieved and it can tolerate some extent frequency detuning. Moreover, the system shows similar chaos-pass filtering effect on unidireetionally coupled system even both VCSELs are modulated. This system allows simultaneously bidirectional secure message transmission on public channels.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10174057 and 90201011）, and the Foundation for Key Program of Ministry of Education, China （Grant No 2005-105148）.
文摘Polarization switching （PS） dynamics and synchronization performances of two mutually coupled vertical-cavity surface-emitting lasers （VCSELs） are studied theoretically in this paper. A group of dimensionless rate equations is derived to describe our model. While analysing the PS characteristics, we focus on the effects of coupling rate and frequency detuning regarding different mutual injection types. The results indicate that the x-mode injection defers the occurrence of PS, while the y-mode injection leads the PS to occur at a lower current. Strong enough polarization-selective injection can suppress the PS. Moreover, if frequency detuning is considered, the effects of polarization-selective mutual injection will be weakened. To evaluate the synchronization performance, the correlation coefficients and output dynamics of VCSELs with both pure mode and mixed mode polarizations are given. It is found that performance of complete synchronization is sensitive to the frequency mismatch but it is little affected by mixed mode polarizations, which is opposite to the case of injection-locking synchronization.
基金supported by the Higher Education Commission of Pakistan through the Indigenous 5000 Ph.D.Fellowship Program(Phase II,Batch II)
文摘This paper addresses the control law design for synchronization of two different chaotic oscillators with mutually Lipschitz nonlinearities. For analysis of the properties of two different nonlinearities, an advanced mutually Lipschitz condition is proposed. This mutually Lipschitz condition is more general than the traditional Lipschitz condition. Unlike the latter, it can be used for the design of a feedback controller for synchronization of chaotic oscillators of different dynamics. It is shown that any two different Lipschitz nonlinearities always satisfy the mutually Lipschitz condition. Applying the mutually Lipschitz condition, a quadratic Lyapunov function and uniformly ultimately bounded stability, easily designable and implementable robust control strategies utilizing algebraic Riccati equation and linear matrix inequalities, are derived for synchronization of two distinct chaotic oscillators. Furthermore, a novel adaptive control scheme for mutually Lipschitz chaotic systems is established by addressing the issue of adaptive cancellation of unknown mismatch between the dynamics of different chaotic systems. The proposed control technique is numerically tested for synchronization of two different chaotic Chua＇s circuits and for obtaining identical behavior between the modified Chua＇s circuit and the R6ssler system.
基金National Natural Science Foundation of China under Grant No.60471023
文摘Understanding the cause of the synchronization of population evolution is an important issue for ecologicalimprovement.Here we present a Lotka-Volterra-type model driven by two correlated environmental noises and show,via theoretical analysis and direct simulation,that noise correlation can induce a synchronization of the mutualists.Thetime series of mutual species exhibit a chaotic-like fluctuation,which is independent of the noise correlation,however,the chaotic fluctuation of mutual species ratio decreases with the noise correlation.A quantitative parameter defined forcharacterizing chaotic fluctuation provides a good approach to measure when the complete synchronization happens.
文摘This paper studies the problem of isochronal synchronization of chaotic systems with time-delayed mutual coupling. Based on the invariance principle of differential equations, an adaptive feedback scheme is proposed for the stability of isochronal synchronization between two identical chaotic systems. Unlike the usual linear feedback, the variable feedback strength is automatically adapted to isochronally synchronize two identical chaotic systems with delay-coupled, so this scheme is analytical, and simple to implement in practice. Simulation results show that the isochronal synchronization behavior is determined by time delay.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.11775019 and 11875086)。
文摘We investigate the transient spontaneous quantum synchronization between two qubits interacting with a common non-Markovian environment based on a collision model.We are mainly interested in the effect of non-Markovianity on the synchronization between two qubits.We find that the non-Markovianity always delay the anti-synchronization and decrease the parameter region where the qubits get anti-synchronized.Meanwhile,we define V to characterize the visibility of synchronization and show that there is an apparent link among V,entanglement and quantum mutual information whether in the Markovian or non-Markovian regimes when the environment is in the vacuum state.Moreover,with the increase of temperature,the parameter region of the emergence of anti-synchronization and the time to get anti-synchronized in the non-Markovian regime gradually approaches that in the Markovian regime.The high temperature decreases the parameter region of the emergence of anti-synchronization in both Markovian and non-Markovian regimes,and breaks the connection among V,entanglement and quantum mutual information.
文摘We perform an analysis of brain-neuromuscular synchronization and coupling strength in muscular dystrophy before and after NPT treatment. In order to estimate with accuracy the level of brain synchronization, we introduce and use the method of the cross GMI that was elaborated by Pompe. The finality is to account for the nonlinear chaotic dynamic contributions that regulate the dynamics. We find that this method is excellent and it may be applied in such case of sEMG and EEG study as well as at a general neurological level. By it we arrive to quantify the coupling strength and synchronization first between two muscular sections (left and right trapezes) and after between Brain activity, as recorded by the EEG, and the trapezes. We compare the results before and after the NPT treatment and we find that the improvement obtained following such treatment is very consistent. We have now in progress other studies relating in particular the application of such new methodologies to other more serious pathologies as the HSP (Hereditary Spastic Paraplegia).
基金The project supported by Nuclear Science Foundation of China and the National Project of Science and Technology for REturned Students.
文摘Coupled oscillators are common in many scientific areas,such as optics,communications,engi-neering,biology,etc.The synchronization of oscillators has important practical applications.This letter focuses on synchronization of coupled hyperchaotic oscillators,which exists in natureand in laboratory and is very important.
文摘Synchronized distributed measurements of mode parameters create a technical feasibility for development and implementing new technologies of control the mode stability and the admissibility of EPS （electric power system） mode. Discussion will focus on different models obtained from data synchronized measurements for operational and automatic emergency control without EPS being totally controlled. According to the proposed technology, the generator＇s output power restrictions are determined in real-time by the terms a static stability using the generators＇ mode model as a multipole with connection nodes of generators＇ electromotive forces （the matrix of SMA （self and mutual admittances） of electromotive forces of generators）. Potential applications of the technology are distribution network with the main substation and generators of commensurable capacity, and transmission network with large power plants （generators） distributed into the network. The one-level control system for all of generators with defining the generator＇s power limits relative to the main substation is implemented in the first case. In the second case, the two-level control system is brought in, based on the separation of large and small generation motion. The results of the method and technology efficiency verification are shown in the paper, by both computer simulations of the power system modes and its physical model.
基金supported by the National Key R&D Program of China(Grant No.2022YFB3206800)the National Natural Science Foundation of China(Grant Nos.62271469,62201547,61901440,and 62074164)+3 种基金the Science and Disruptive Technology Program of Aerospace Information Research Institute,Chinese Academy of Sciencesthe One Hundred Person Project of the Chinese Academy of Sciencesthe Young Elite Scientists Sponsorship Program by China Association for Science and Technology(Grant No.YESS20210341)the Xiaomi Young Talents Program。
文摘The synchronization of nonlinear systems has been demonstrated in several natural systems,which not only enhances the performance of spin torque oscillators(STOs)but also enables the modification of STOs for new computing architectures.This paper reviews recent advances in the mutual synchronization,forced synchronization,and noise synchronization of STOs from both theoretical and experimental perspectives.The main types of synchronization discussed include spin wave synchronization,dipolar field synchronization,electrical connection synchronization,and injection locking.After introducing the theoretical and experimental progress in these fields,we highlight the importance of synchronization for practical applications in both microwave devices and neuromorphic computing.The significance of these studies for understanding and applying STO synchronization is emphasized,and we offer our perspective on current research,suggesting directions for future studies.
基金the National Natural Science Foundation of China (No.10174057 and 90201011)the Key Project of Chinese Ministry of Education (No.105148).
文摘Two vertical-cavity surface-emitting lasers（VCSELs） are mutually coupled through a partially transparent mirror （PTM） placed in the pathway. The PTM plays the role of external mirror, which controls the feedback strength and coupling strength. We numerically simulate this system by establishing a visible SIMULINK model. The results demonstrate that the anticipation synchronization is achieved and it can tolerate some extent frequency detuning. Moreover, the system shows similar chaos-pass filtering effect on unidireetionally coupled system even both VCSELs are modulated. This system allows simultaneously bidirectional secure message transmission on public channels.
