Feedback Control on Einstein-Podolsky-Rosen Steering of Dissipative System

Zhiming Huang

Fei Wang, Jun Xu, Guangling Cheng +1 more

Benyuan Zhou, Ni Pan, Li Yu +1 more

We propose a scheme to manipulate entanglement and the direction of asymmetric Einstein-Podolsky-Rosen (EPR) steering between two interacting bosonic modes in a nonlinear optical apparatus, in which a pumped Fabry-P\'erot cavity system containing two nonlinear waveguides is coupled to two feedback loops. It is found that Markovian feedback plays a key role in controlling both entanglement and EPR steering, the maximal entanglement can only be achieved through two symmetric feedback loops, while one-way EPR steering can only occur when both asymmetric feedback loops and an unbalanced beam-splitter are satisfied simultaneously. Furthermore, in terms of an unequal beam-splitter and two different feedback loops, it is demonstrated that the directionality and extent of the asymmetric EPR steering can be readily controlled under certain conditions. A simple and sufficient condition is also revealed for generating two-way EPR steering. Moreover, the entanglement and EPR steering can be effectively enhanced by performing Markovian feedback. In addition, By choosing appropriate feedback strengths, two cavity modes can be driven into a pure two-mode squeezed vacuum state rather than a mixed two-mode Gaussian entangled state or a pure entangled dark state. We hope the proposed scheme will enhance our understanding of the fundamental asymmetry of EPR steering, and it may have potential applications in quantum computation and quantum communication.

Qi Guo, Mei‐Rong Wei, Cheng‐Hua Bai +3 more

We consider a three-mode optomechanical system in which two mechanical oscillators are independently coupled to a cavity mode driven by two controllable lasers. By controlling the two-tone driving, one can prepare the entanglement and Einstein-Podolsky-Rosen (EPR) steering of two mechanical modes, in which the cavity mode acts as a single reservoir to cool two Bogoliubov modes. We find that the direction of EPR steering can be manipulated effectively by adjusting the damping rates and the thermal noises of two mechanical modes. In addition, we show that the entanglement and EPR steering between two mechanical modes can be enhanced by adding a parametric amplifier (PA) into the cavity. The effects of the strength and phase of the PA on the mechanical entanglement and EPR steering are analyzed and discussed in detail. Meanwhile, the additional PA can also expand the region of the one-way steering and strengthen the robustness of the entanglement and EPR steering against the thermal noise. The present scheme may provide effective resources for quantum information processing.

Kai Sun, Xiang-Jun Ye, Jin‐Shi Xu +2 more

Mengxin Zhang, Yumei Long, Shiqing Zhao +1 more

We achieve the controllable multipartite Einstein-Podolsky-Rosen (EPR) steering and its monogamy relations by means of the dynamical Casimir effect in the frame of superconducting quantum network. We employ the external driving flux of the superconducting quantum interference device as a switch. It is interesting that the system exhibits different types of the EPR steering and monogamy relations by tuning parameters. In the system, the one-way or two-way EPR steerings for different parties have been realized, and the direction of the one-way EPR steering is reversed by tuning coupling parameters. Remarkably, we can also obtain the EPR steering orderly sudden death for different modes. In addition, the system not only shows the type-I and type-II monogamy relations, but also converts steering parties to get monogamy relations' swapping and cycling. Finally, we discuss the influence of temperature. In the system, the higher the temperature is, the earlier sudden death for the EPR steering is. These results are important for quantum information and lay a foundation for us to better understand the important role of the multipartite EPR steering in secure quantum communication.