Zhang Zuo-Yuan, Wei Daxiu, Hu Zhengfeng, Liu Jin-Ming
State Key Laboratory of Precision Spectroscopy, East China Normal University Shanghai 200062 China
Department of Physics and Shanghai Key Laboratory of Magnetic Resonance, East China Normal University Shanghai 200062 China.
RSC Adv. 2018 Oct 23;8(63):35928-35935. doi: 10.1039/c8ra06342g. eCollection 2018 Oct 22.
Einstein-Podolsky-Rosen (EPR) steering gives evidence for the phenomenon called "spooky action at a distance" in quantum mechanics, and provides a useful resource for the implementation of quantum information tasks. In this paper, we consider a pair of ultracold polar molecules trapped in an external electric field as a promising quantum information carrier, and analyze the evolution behavior of EPR steering for the two coupled polar molecules in pendular states. Our results show that the steering of the two linear dipoles is remarkably reliant upon the Stark effect and dipole-dipole interaction. To be specific, the steerability degree is inversely associated with the intensity of the electric field while it is positively correlated with the coupling strength between the two polar molecules. Moreover, it is found that high ambient temperature can lead to a rapid loss of the steerable resource in thermal equilibrium. Further, we put forward an effective strategy to enhance the steerability using the technique of weak measurement reversal (WMR). By taking into account the influence of intrinsic decoherence on the steering dynamics, we found that robust EPR steering preservation can be realized for the initial state being in the Bell state . Our findings may shed some new light on molecular quantum information processing with pendular states.
爱因斯坦 - 波多尔斯基 - 罗森（EPR）操控为量子力学中所谓的“幽灵般的超距作用”这一现象提供了证据，并为量子信息任务的实现提供了一种有用的资源。在本文中，我们将一对被困在外部电场中的超冷极性分子视为一种有前景的量子信息载体，并分析处于摆动态的两个耦合极性分子的EPR操控的演化行为。我们的结果表明，两个线性偶极子的操控显著依赖于斯塔克效应和偶极 - 偶极相互作用。具体而言，可操控程度与电场强度成反比，而与两个极性分子之间的耦合强度成正比。此外，发现高温会导致热平衡中可操控资源的快速损失。进一步地，我们提出了一种利用弱测量反转（WMR）技术增强可操控性的有效策略。通过考虑本征退相干对操控动力学的影响，我们发现对于处于贝尔态的初始态可以实现稳健的EPR操控保持。我们的发现可能为具有摆动态的分子量子信息处理带来一些新的启示。
