Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune 411 008, India.
Phys Rev E. 2017 Jan;95(1-1):012216. doi: 10.1103/PhysRevE.95.012216. Epub 2017 Jan 27.
Quantum correlations reflect the quantumness of a system and are useful resources for quantum information and computational processes. Measures of quantum correlations do not have a classical analog and yet are influenced by classical dynamics. In this work, by modeling the quantum kicked top as a multiqubit system, the effect of classical bifurcations on measures of quantum correlations such as the quantum discord, geometric discord, and Meyer and Wallach Q measure is studied. The quantum correlation measures change rapidly in the vicinity of a classical bifurcation point. If the classical system is largely chaotic, time averages of the correlation measures are in good agreement with the values obtained by considering the appropriate random matrix ensembles. The quantum correlations scale with the total spin of the system, representing its semiclassical limit. In the vicinity of trivial fixed points of the kicked top, the scaling function decays as a power law. In the chaotic limit, for large total spin, quantum correlations saturate to a constant, which we obtain analytically, based on random matrix theory, for the Q measure. We also suggest that it can have experimental consequences.
量子关联反映了系统的量子特性，是量子信息和计算过程的有用资源。量子关联的度量没有经典类比，但却受到经典动力学的影响。在这项工作中，通过将量子受迫陀螺建模为多量子比特系统，研究了经典分岔对量子关联度量（如量子失谐、几何失谐和 Meyer 和 Wallach Q 度量）的影响。在经典分岔点附近，量子关联度量变化迅速。如果经典系统在很大程度上是混沌的，那么关联度量的时间平均值与通过考虑适当的随机矩阵集合获得的值非常吻合。量子关联与系统的总自旋成正比，代表其半经典极限。在受迫陀螺的平凡平衡点附近，标度函数呈幂律衰减。在混沌极限下，对于大的总自旋，量子关联会饱和到一个常数，我们根据随机矩阵理论，从理论上得到了 Q 度量的这个常数。我们还提出它可能具有实验意义。
