The stabilization of a class of switched nonlinear systems is investigated in the paper. The systems concerned are of （generalized） switched Byrnes-Isidori canonical form, which has all switched models in （generali...The stabilization of a class of switched nonlinear systems is investigated in the paper. The systems concerned are of （generalized） switched Byrnes-Isidori canonical form, which has all switched models in （generalized） Byrnes- Isidori canonical form. First, a stability result of switched systems is obtained. Then it is used to solve the stabilization problem of the switched nonlinear control systems. In addition, necessary and sufficient conditions are obtained for a switched affine nonlinear system to be feedback equivalent to （generalized） switched Byrnes-Isidori canonical systems are presented. Finally, as an application the stability of switched lorenz systems is investigated.展开更多
We propose and discuss a novel concept of robust set stabilization by permissible controls; this concept is helpful when dealing with both a priori information of model parameters and different permissible controls in...We propose and discuss a novel concept of robust set stabilization by permissible controls; this concept is helpful when dealing with both a priori information of model parameters and different permissible controls including quantum measurements. Both controllability and stabilization can be regarded as the special case of the novel concept. An instance is presented for a kind of uncertain open quantum systems to further justify this gen- eralized concept. It is underlined that a new type of hybrid control based on periodically perturbed projective measurements can be the permissible control of uncertain open quantum systems when perturbed projective measurements are available. The sufficient conditions are given for the robust set stabilization of uncertain quantum open systems by the hybrid control, and the design of the hybrid control is reduced to selecting the period of measurements.展开更多
Dynamical decoupling (DD) eliminates qubit-bath coupling by applying a sequence of instantaneous pulses.While qubit-bath couplings generally lead to qubit relaxation and dephasing,qubit-qubit couplings are often used ...Dynamical decoupling (DD) eliminates qubit-bath coupling by applying a sequence of instantaneous pulses.While qubit-bath couplings generally lead to qubit relaxation and dephasing,qubit-qubit couplings are often used to manipulate or control quantum states.We investigate the available control operations in two DD schemes,named periodic DD (PDD) and Uhrig DD (UDD),to see whether universal quantum computation can be realized in these decoupled systems.We find that universal control is possible using Heisenberg interaction in both periodically decoupled system and Uhrig decoupled system,and the available control operations under two kinds of DD sequences obey the same commutation relation.In the UDD case,we also derive a rough bound for control errors.展开更多
Fast and high fidelity quantum control is the key technology of quantum computing. The hybrid system composed of the nitrogen-vacancy center and nearby Carbon-13 nuclear spin is expected to solve this problem. The nit...Fast and high fidelity quantum control is the key technology of quantum computing. The hybrid system composed of the nitrogen-vacancy center and nearby Carbon-13 nuclear spin is expected to solve this problem. The nitrogen-vacancy center electron spin enables fast operations for its strong coupling to the control field, whereas the nuclear spins preserve the coherence for their weak coupling to the environment. In this paper, we describe a strategy to achieve time-optimal control of the Carbon-13 nuclear spin qubit by alternating controlling the nitrogen-vacancy center electron spin as an actuator. We transform the qubit gate operation into a switched system. By using the maximum principle, we study the minimum time control of the switched system and obtain the time-optimal control of the qubit gate operation. We show that the X gate and Y gate operations are within 10μs while the fidelity reaches 0.995.展开更多
Dr. Daizhan Cheng is a full professor of the Key Lab of Systems and Control, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, and was the former Editor-in-Chief of this journal, Control Theory ...Dr. Daizhan Cheng is a full professor of the Key Lab of Systems and Control, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, and was the former Editor-in-Chief of this journal, Control Theory and Technology （whose original title was Journal of Control Theory and Applications before 2013） during 2003-2013. He was born in March 1946 and got his Ph.D. degree from Washington University, USA. Prof. Cheng contributed much to several control fields, especially to nonlinear control systems, networked or switched systems, logic dynamic systems, and numerical realization of control design, and published over 10 books and 120 journal papers. Because of his outstanding research achievement, he won National Natural Science Award of China twice （in 2008 and 2014, respectively） and Automatica 2008-2010 Theory/Methodology Best Paper Award （in 2011 ）. He is also an IEEE Fellow （2005-） and an IFAC Fellow （2008-） for his international influence.展开更多
基金This work is partly supported by the National Natural Science Foundation of China (No. 60274010, 60221301, 60334040, 60228003).
文摘The stabilization of a class of switched nonlinear systems is investigated in the paper. The systems concerned are of （generalized） switched Byrnes-Isidori canonical form, which has all switched models in （generalized） Byrnes- Isidori canonical form. First, a stability result of switched systems is obtained. Then it is used to solve the stabilization problem of the switched nonlinear control systems. In addition, necessary and sufficient conditions are obtained for a switched affine nonlinear system to be feedback equivalent to （generalized） switched Byrnes-Isidori canonical systems are presented. Finally, as an application the stability of switched lorenz systems is investigated.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61673389,61273202 and 61134008
文摘We propose and discuss a novel concept of robust set stabilization by permissible controls; this concept is helpful when dealing with both a priori information of model parameters and different permissible controls including quantum measurements. Both controllability and stabilization can be regarded as the special case of the novel concept. An instance is presented for a kind of uncertain open quantum systems to further justify this gen- eralized concept. It is underlined that a new type of hybrid control based on periodically perturbed projective measurements can be the permissible control of uncertain open quantum systems when perturbed projective measurements are available. The sufficient conditions are given for the robust set stabilization of uncertain quantum open systems by the hybrid control, and the design of the hybrid control is reduced to selecting the period of measurements.
基金supported by the National Natural Science Foundation of China(60774099,60821091,61134008)
文摘Dynamical decoupling (DD) eliminates qubit-bath coupling by applying a sequence of instantaneous pulses.While qubit-bath couplings generally lead to qubit relaxation and dephasing,qubit-qubit couplings are often used to manipulate or control quantum states.We investigate the available control operations in two DD schemes,named periodic DD (PDD) and Uhrig DD (UDD),to see whether universal quantum computation can be realized in these decoupled systems.We find that universal control is possible using Heisenberg interaction in both periodically decoupled system and Uhrig decoupled system,and the available control operations under two kinds of DD sequences obey the same commutation relation.In the UDD case,we also derive a rough bound for control errors.
基金This work was supported by the National Natural Science Foundation of China （Nos. 61227902, 61573343） and the National Center for Mathematics and Interdisciplinary Sciences, CAS.
文摘Fast and high fidelity quantum control is the key technology of quantum computing. The hybrid system composed of the nitrogen-vacancy center and nearby Carbon-13 nuclear spin is expected to solve this problem. The nitrogen-vacancy center electron spin enables fast operations for its strong coupling to the control field, whereas the nuclear spins preserve the coherence for their weak coupling to the environment. In this paper, we describe a strategy to achieve time-optimal control of the Carbon-13 nuclear spin qubit by alternating controlling the nitrogen-vacancy center electron spin as an actuator. We transform the qubit gate operation into a switched system. By using the maximum principle, we study the minimum time control of the switched system and obtain the time-optimal control of the qubit gate operation. We show that the X gate and Y gate operations are within 10μs while the fidelity reaches 0.995.
文摘Dr. Daizhan Cheng is a full professor of the Key Lab of Systems and Control, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, and was the former Editor-in-Chief of this journal, Control Theory and Technology （whose original title was Journal of Control Theory and Applications before 2013） during 2003-2013. He was born in March 1946 and got his Ph.D. degree from Washington University, USA. Prof. Cheng contributed much to several control fields, especially to nonlinear control systems, networked or switched systems, logic dynamic systems, and numerical realization of control design, and published over 10 books and 120 journal papers. Because of his outstanding research achievement, he won National Natural Science Award of China twice （in 2008 and 2014, respectively） and Automatica 2008-2010 Theory/Methodology Best Paper Award （in 2011 ）. He is also an IEEE Fellow （2005-） and an IFAC Fellow （2008-） for his international influence.
