Markov Quantum Feedback Control Based on Homodyne Measurement of a Two-Qubit System

【摘要】 <正> We consider the system consisting of two qubits collectively damped,with the output being unit-efficiencymeasured and subsequently fed back to control the system state.Our primary goal in this paper is (ⅰ) to solve thefeedback-modified master equation,(ⅱ) to demonstrate the ability of feedback control based on the solutions,and (ⅲ) topick out different steady states by choosing different driving strengths and feedback strengths to counteract the effects ofboth damping and the measurement back-action on the system.We further investigate some properties of the equilibriumsteady state,its distribution probability and entanglement vs.the driving and feedback amplitudes.We find that in ourfeedback model feedback plays a negative role in producing entanglement.更多还原

【Abstract】 We consider the system consisting of two qubits collectively damped,with the output being unit-efficiency measured and subsequently fed back to control the system state.Our primary goal in this paper is (ⅰ) to solve the feedback-modified master equation,(ⅱ) to demonstrate the ability of feedback control based on the solutions,and (ⅲ) to pick out different steady states by choosing different driving strengths and feedback strengths to counteract the effects of both damping and the measurement back-action on the system.We further investigate some properties of the equilibrium steady state,its distribution probability and entanglement vs.the driving and feedback amplitudes.We find that in our feedback model feedback plays a negative role in producing entanglement.更多还原