High-performance control of quantum dynamics is key to the development of quantum technologies.From quantum-state engineering to quantum metrology,theory and practice of quantum control enable robust and cheaper techn...High-performance control of quantum dynamics is key to the development of quantum technologies.From quantum-state engineering to quantum metrology,theory and practice of quantum control enable robust and cheaper technologies for future industrial applications.Starting from fundamental matter–field interactions, we overview various approaches to modelling quantum control systems, in which control can be implemented by either changing field or material properties. These models are built in time or frequency domain and can be interconnected to form quantum feedback networks. This review can be taken as a useful reference for engineers to understand the quantum physics behind, or for physicists to resolve control problems from a control engineering point of view.展开更多
SU（1,1） dynamical symmetry is of fundamental importance in analyzing unbounded quantum systems in theoretical and applied physics. In this paper, we study the control of generalized coherent states associated with q...SU（1,1） dynamical symmetry is of fundamental importance in analyzing unbounded quantum systems in theoretical and applied physics. In this paper, we study the control of generalized coherent states associated with quantum systems with SU（1,1） dynamical symmetry. Based on a pseudo Riemannian metric on the SU（1,1） group, we obtain necessary conditions for minimizing the field fluence of controls that steer the system to the desired final state. Further analyses show that the candidate optimal control solutions can be classified into normal and abnormal extremals. The abnormal extremals can only be constant functions when the control Hamiltonian is non-parabolic, while the normal extremals can be expressed by Weierstrass elliptic functions according to the parabolicity of the control Hamiltonian. As a special case, the optimal control solution that maximally squeezes a generalized coherent state is a sinusoidal field, which is consistent with what is used in the laboratory.展开更多
lnkjet printing （IJP） synthesis has emerged as a useful technique for the fabrication of functional metal oxides in the fields of nanotechnology and materials science. In this paper, we will review the fundamental s...lnkjet printing （IJP） synthesis has emerged as a useful technique for the fabrication of functional metal oxides in the fields of nanotechnology and materials science. In this paper, we will review the fundamental state-of-the-art principles of the special ink formulations used for IJP synthesis of functional metal oxides and the applications of these oxides.展开更多
In quantum circuits, importing of additional qubits can reduce the operation time and prevent decoherence induced by the environment. However, excessive qubits may make the quantum system vulnerable. This paper descri...In quantum circuits, importing of additional qubits can reduce the operation time and prevent decoherence induced by the environment. However, excessive qubits may make the quantum system vulnerable. This paper describes how to relax existing qubits without additional qubits to significantly reduce the operation time of the quantum Fourier circuit compared to a circuit without optimization. The results indicate that this scheme makes full use of the qubits relaxation. The concepts can be applied to improve similar quantum circuits and guide the physical implementations of quantum algorithms or devices.展开更多
基金supported by the National Natural Science Foundation of China(61374091 and 61134008)
文摘High-performance control of quantum dynamics is key to the development of quantum technologies.From quantum-state engineering to quantum metrology,theory and practice of quantum control enable robust and cheaper technologies for future industrial applications.Starting from fundamental matter–field interactions, we overview various approaches to modelling quantum control systems, in which control can be implemented by either changing field or material properties. These models are built in time or frequency domain and can be interconnected to form quantum feedback networks. This review can be taken as a useful reference for engineers to understand the quantum physics behind, or for physicists to resolve control problems from a control engineering point of view.
基金supported by the National Natural Science Foundation of China(Nos.61374091,61134008)
文摘SU（1,1） dynamical symmetry is of fundamental importance in analyzing unbounded quantum systems in theoretical and applied physics. In this paper, we study the control of generalized coherent states associated with quantum systems with SU（1,1） dynamical symmetry. Based on a pseudo Riemannian metric on the SU（1,1） group, we obtain necessary conditions for minimizing the field fluence of controls that steer the system to the desired final state. Further analyses show that the candidate optimal control solutions can be classified into normal and abnormal extremals. The abnormal extremals can only be constant functions when the control Hamiltonian is non-parabolic, while the normal extremals can be expressed by Weierstrass elliptic functions according to the parabolicity of the control Hamiltonian. As a special case, the optimal control solution that maximally squeezes a generalized coherent state is a sinusoidal field, which is consistent with what is used in the laboratory.
基金the National Natural Science Foundation of China(grant Nos.21222307,21271153,51222202,J1210042 and 21003106)the Fok Ying Tung Education Foundation(grant No.131015)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(grant No.R12B030002)the Fundamental Research Funds for the Central Universities(grant No.2012QNA3014) for their financial support
文摘lnkjet printing （IJP） synthesis has emerged as a useful technique for the fabrication of functional metal oxides in the fields of nanotechnology and materials science. In this paper, we will review the fundamental state-of-the-art principles of the special ink formulations used for IJP synthesis of functional metal oxides and the applications of these oxides.
基金the National Natural Science Foundation of China (Nos. 60433050 and 60274025)the U.S. Army Research Office (No. W911NF-04-1-0386)
文摘In quantum circuits, importing of additional qubits can reduce the operation time and prevent decoherence induced by the environment. However, excessive qubits may make the quantum system vulnerable. This paper describes how to relax existing qubits without additional qubits to significantly reduce the operation time of the quantum Fourier circuit compared to a circuit without optimization. The results indicate that this scheme makes full use of the qubits relaxation. The concepts can be applied to improve similar quantum circuits and guide the physical implementations of quantum algorithms or devices.
