级联环境下两量子比特Bell非定域性和量子相干动力学  

The Dynamics of Bell Non-locality and Quantum Coherence for Two Qubits under the Hierarchical Environment

作　　者：张艳秋 李军奇[1] ZHANG Yan-qiu;LI Jun-qi(Institute of Theoretical Physics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学理论物理研究所,山西太原030006

出　　处：《量子光学学报》2022年第3期187-194,共8页Journal of Quantum Optics

基　　金：国家自然科学基金(U21A20433,11105087,12147215)。

摘　　要：本文基于与各自的级联环境相互耦合的两量子比特系统,详细讨论了弱、强耦合体系下量子比特与腔之间的耦合强度κ以及腔频率与库的中心频率之间的失谐量δ对Bell非定域性和量子相干动力学的影响。结果表明:在两种耦合体系中,均存在Bell非定域性猝死现象,且Bell非定域性的存活时间或量值随κ和δ的改变而改变。相比之下,量子相干展现了塌缩、复苏等行为,复苏的峰值随κ和δ的增大而增大。此外,我们进一步考察了量子弱测量和测量反转操作对Bell非定域性和量子相干的有效调制作用,获得一些有意义的结果。Bell non-locality and quantum coherence are two fascinating properties of quantum systems.They are not only of fundamental importance,but also crucial resources in quantum information processing.Bell non-locality refers to the quantum correlation that violates Bell inequality and cannot be explained by any local hidden variable model.Meanwhile,the violation of Bell inequality can also be used to indicate the existence of entanglement.Quantum coherence,arising from the quantum state superposition,marks the violation of quantum mechanics from the classical world,and is recognized as the foundation of quantum correlation.Due to the unwanted interaction between a quantum system and the environment,Bell non-locality and quantum coherence can be degraded.Thus,in order to utilize them better,much effort has been devoted to investigating the dynamics of Bell non-locality and quantum coherence in the open quantum systems with the single-layered environment.However,in fact,the quantum system can be affected by the hierarchical environment too,which is receiving increasing attention at present.Under this background,we explore in this paper the dynamics of Bell non-locality and quantum coherence of two identical qubits,each of them is coupled independently to its own hierarchical environment.The effects of coupling strengthκbetween the qubit and cavity,and the detuningδbetween the frequency of cavity and the center frequency of reservoir on the dynamics of Bell non-locality and quantum coherence have been discussed in detail for the weak and strong coupling regimes.It has been shown that there exists the sudden death phenomenon of Bell non-locality in both coupling regimes.Meanwhile,the survival time or the value of Bell non-locality changes withκandδ.In contrast,quantum coherence presents collapsing,revival,and other behaviors,and the peak value of revival will increase with the increase ofκandδ.Moreover,the effective manipulation of quantum weak measurement and measurement reversal operation on Bell non-locality and

关 键 词：Bell非定域性 量子相干 弱测量 级联环境 

分 类 号：O413.1[理学—理论物理]