弱测量操作后的量子纠缠态的可逆性

Reversibility of Weak Measured Quantum Entanglement States

对弱测量操作后的量子纠缠态实施可逆性操作,采用共生纠缠的方法度量纠缠态的强度,分析对比初始纠缠态强度和弱测量操作后的纠缠强度,探究对弱测量后的量子纠缠态逆转的可行性。以两体量子纠缠态为例,将处于纠缠态的两二能级原子分别置于高品质真空腔场中并进行弱测量操作和可逆性操作,研究两体系统量子纠缠态纠缠强度的动力学特性。数值分析表明,弱测量操作后通过可逆性操作可以实现系统量子纠缠的恢复,弱测量后量子态纠缠强度经可逆性操作可使其恢复到初始状态值,即通过可逆性操作方案可修复弱测量对量子态的干扰影响。

Quantum entangled states, as an important resource for quantum communication and information, can obtain relevant information about their quantum states can be measured to obtain. Projection measurement can cause the initial state to collapse to one of its eigenstate. It cannot be used to reverse the measured quantum state to its initial state. If the weak measurement operation is applied to the quantum entangled state and the corresponding reversibility operation is used to explore the elimination effect of its weak measurement on the perturbation of the quantum entangled state, it has certain significance. Therefore, the study of the reversibility of quantum entangled states under different initial conditions after weak measurement and analyzing the feasibility of inverting the quantum entangled state after weak measurement operation to its initial state after reversibility operation is significant. Using weak measurement schemes and reversible operations, numerical analysis of the weak measured quantum state is theoretically carried out, exploring the realization of the inversion of the weak measured quantum state. By implementing reversible operation on the quantum entanglement state after weak measurement operation, this work mainly explores the reversal behavior of the entanglement strength of the quantum entangled state. Concurrence is used to measure the entanglement strength of quantum entanglement states before and after weak measurement. And the entanglement strength of the initial quantum entangled state and the entanglement strength after weak measurement operation are analyzed. Taking a two-body quantum entangled state as an example, two entangled two-level atoms are respectively placed in a high-quality vacuum cavity field. By considering the weak measurement and reversible operation to one atom, we explore the dynamic characteristics of the two-body system quantum entangled state under this scheme.The numerical analysis results show that the entanglement strength of the quantum state after weak measurement can be fully reversed to its initial value through an appropriate reversibility operation. That is to say, the interference of weak measurement on quantum state can be repaired through the reversible operation.