Researches On Manipulation Of Superconducting Qubits System State

The establishment of quantum mechanics is epoch-making milestone in the 20 th century physics. It has been a huge success for the past one hundred years, In addition it has been deep into the different aspects in the production of social life. The quantum system control theory has been raised along with the quantum theory, this isa disciplinary interspersed with the quantum theory, control theory, information technology and computer science and other multi-disciplinary. People have been concern it since the 1980 s. In recent years, People has made many research results in this aspect. Received many good effect when those results been applied to the quantum chemistry or quantum information and the new nanotechnology. It has become the second in one hundred in quantum physics field. This paper research on the core components of manipulation of the Josephson knot superconductivity charge qubits system state. It mainly including the following two contents:Firstly, manipulation of superconductivity charge qubits system using optimal control theory. Superconductivity charge qubits system state been described by the schrodinger equation. This equation can rewrite another form where add a fictitious control quantity that it can change the global phase without affecting the probability distribution. There, we can design the control law through setting performance indicators on the basis of the schrodinger equation rewrite form. We can select the performance index based on the quantum system characteristics. The resulting of control law by proved not only to be optimal, but also it can guarantee the stability of the regulation system. The numerical simulation shows that:manipulation the superconductivity charge qubits system state has be completed; Contrast analysis of the simulation results when we chose the different parameters.Secondly, We manipulation the superconducting charge qubits system by using the control theory of Lyapunov. The classical Lyapunov stability theory was applied to regulation of superconductivity charge qubits system state. First of all, we setting the target state is intrinsic state. At present, we can design the control law when the control function been selected the control theory of Lyapunoy sense based on the deviation or distance between the system state. For such a case of quantum systems,we adopt direct and indirect control respectively when analyses the structure form of the Hamiltonian. Take numerical simulation for this quantum system. Not only based on the quantum system deviation but also based on the quantum system distance, We also chose different amplitude of control and comparative analysis of simulation results. For another, Setting the target state is superposition state: ? 0 ?1? / 2.Selection the control function based on the deviation of form of Lyapunov sense.According to the control strategy for numerical simulation. Results show that the state completely tun over to the target state, and the system can keeping stable. We also analyzed the effects under the different extent of control. General speaking, The control law is designed based on Lyapunov stability theory that it can be done state transition and ensure system stability. Compared with the optimal control strategy this control method can save complex iterative calculation. So this is a kind of success control method.