Wang Yiding, Zhang Tinggui, Huang Xiaofen, Fei Shao-Ming
School of Mathematics and Statistics, Hainan Normal University, Haikou 571158, China.
School of Mathematical Sciences, Capital Normal University, Beijing 100048, China.
iScience. 2025 Mar 10;28(4):112174. doi: 10.1016/j.isci.2025.112174. eCollection 2025 Apr 18.
We present a nonlinear entanglement detection strategy that detects entanglement that the linear detection strategy fails. We show that when the nonlinear entanglement detection strategy fails to detect the entanglement of an entangled state with two copies, it may succeed with three or more copies. Based on our strategy, a witness combined with a suitable quantum mechanical observable may detect the entanglement that cannot be detected by the witness alone. Moreover, our strategy can also be applied to detect multipartite entanglement by using the witnesses for bipartite systems, as well as to entanglement concentrations.
我们提出了一种非线性纠缠检测策略，该策略能够检测出线性检测策略无法检测到的纠缠。我们表明，当非线性纠缠检测策略无法检测出具有两个副本的纠缠态的纠缠时，它可能在具有三个或更多副本时成功。基于我们的策略，一个与合适的量子力学可观测量相结合的见证者可以检测出仅靠见证者本身无法检测到的纠缠。此外，我们的策略还可以通过使用二分系统的见证者来应用于检测多体纠缠，以及用于纠缠浓缩。
