比较三种W-like态与W态
Comparing the three W-like states with the W state
浏览论文内容
中文总结 AI 辅助
本文比较了三种W-like态与W态，发现前者的纠缠度更高，更稳健，适用于完美传送和超密集编码，而W态不具此能力。
中文摘要 AI 辅助
在[Phys. Rev. Lett., 98, 260501 (2007)]及之前的论文中，W-like态被用于许多量子通信方案、提纯、传送和超密集编码。迄今为止，没有人将W-like态与W态进行比较。我们研究了三种称为$|\vartheta ^{\prime }\rangle $、$|\eta ^{\prime }\rangle $和$|\xi ^{\prime }\rangle $的W-like态的性质。我们指出，$|\vartheta ^{\prime }\rangle $（resp. $|\eta ^{\prime }\rangle $和$|\xi ^{\prime }\rangle $）具有最大的von Neumann纠缠熵（vNEE）$S(\rho _{A})=\ln 2$（resp. $S(\rho _{B})=\ln 2$和$S(\rho _{C})=\ln 2$）以及最大的tangle$\tau _{A(BC)}=1$（resp. $\tau _{B(AC)}=1$和$\tau _{C(AB)}=1$），而W态不具备。我们还指出，如果某个qubit被追踪出去，那么$|\vartheta ^{\prime }\rangle $（resp. $|\eta ^{\prime }\rangle $和$|\xi ^{\prime }\rangle $）的剩余两个qubit比W态的两个qubit更加纠缠，通过几种纠缠度量。这意味着三种W-like态比W态更稳健地抵抗某些粒子损失。我们证明$|\vartheta ^{\prime }\rangle $、$|\eta ^{\prime }\rangle $和$|\xi ^{\prime }\rangle $可以适用于完美传送和超密集编码，但W态不能。
英文摘要
In [Phy. Rev. Lett., 98, 260501 (2007)] and previous papers, the W-like states were used in many quantum communication schemes, distillation, teleportation and superdense coding. So far, no one has compared the W-like states with the W state. We investigate the properties of three W-like states named as $|\vartheta ^{\prime }\rangle $, $|η^{\prime }\rangle $ and $|ξ^{\prime }\rangle $. We point out that $|\vartheta ^{\prime }\rangle $ (resp. $|η^{\prime }\rangle $ and $|ξ^{\prime }\rangle $) has the maximal von Neumann entanglement entropy (vNEE) $S(ρ_{A})=\ln 2$ (resp. $S(ρ_{B})=\ln 2$ and $S(ρ_{C})=\ln 2$) and the maximal tangle $τ_{A(BC)}=1$ (resp. $τ_{B(AC)}=1$ and $τ_{C(AB)}=1$) while the W state does not. We also indicate that if some one of three qubits is traced out, then the remaining two qubits of $|\vartheta ^{\prime }\rangle $ (resp. $|η^{\prime }\rangle $ and $|ξ^{\prime }\rangle $) are more entangled than the two qubits of the W state by several entanglement measures. It means that the three W-like states have higher robustness against some particle loss than the W state. We show that $|\vartheta ^{\prime }\rangle $, $|η^{\prime }\rangle $ and $|ξ^{\prime }\rangle $ can be suitable for perfect teleportation and superdense coding but the W state cannot.
