利用弱测量保护两个三能级原子系统的束缚纠缠

Protecting Bound Entanglement of Qutrit-qutrit Systems by Weak Measurement

高维量子系统的纠缠态因其诸多的优点而受到广泛的关注。目前,肖兴等人[Eur.Phys.J.D.(2013)67:204]研究了两个V-型三能级原子系统的演化动力学,得到了弱测量方案能保护系统自由纠缠的结论。本文研究了在振幅阻尼噪声中两个全同三能级原子系统束缚纠缠的演化动力学。在振幅阻尼通道中,前置弱测量和后置弱测量反转操作,实现了对系统束缚纠缠的保护。束缚纠缠保持的时间受量子态参数和弱测量强度的影响。相应的物理原因也得到了合理的解释。对于两个非全同三能级原子的情况,此结论依旧成立。另外,弱测量方案并不是对所有类型的束缚纠缠态都适用,有一定的局限性。

Entangled states in high dimensional systems have been concerned widely because of its various advantage.Recently,Xiao Xing and some others[Eur.Phys.J.D.（2013）67：204]have investigated the evolution dynamics of qutrit-qutrit systems,and they have gotten a conclusion that the free entanglement can be protected by the scheme of weak measurement.We investigated the bound entanglement evolution dynamics of two identical qutrits systems under amplitude damping decoherence.By the operation of prior weak measurement and post quantum weak measurement reversal in the amplitude damping channel,we realized the protection of bound entanglement.The last time of bound entanglement was affected by the parameter of quantum state and the strength of weak measurement.A corresponding physical reason was explained.Our conclusion was also satisfied for the condition of two non-identical qutrits systems.By the way,the weak measurement scheme is not suitable for all kinds of bound entanglement,for its some limitation.