论文标题
Wigner spin- $ j $ systems
Wigner negativity in spin-$j$ systems
论文作者
论文摘要
在球形相空间上研究了通过Wigner负性测量的简单自旋系统的非古老性。解决了几个具有共同固定表示形式的SU（2） - 旋转状态：旋转相干，旋转猫（GHz/n00n）和dicke（$ \ textsf {w} $）。我们得出了旋转猫状态的Wigner负性的束缚，该状态迅速接近真实值，因为自旋的增加超过了$ j \ gtrsim 5 $。我们发现，与同等尺寸相比，旋转猫状态并非显着的Wigner阴性。我们还发现，与几种纠缠措施相比，最含有的dicke基元元素是自旋依赖的，而不是赤道状态$ | j，0 \ rangle $（或$ | j，\ pm 1/2 \ rangle $ for Half-Integer Spins）。这些结果强调了动态对称性对非经典性的影响，并提出了寻找新型量子计算应用的指导观点。
The nonclassicality of simple spin systems as measured by Wigner negativity is studied on a spherical phase space. Several SU(2)-covariant states with common qubit representations are addressed: spin coherent, spin cat (GHZ/N00N), and Dicke ($\textsf{W}$). We derive a bound on the Wigner negativity of spin cat states that rapidly approaches the true value as spin increases beyond $j \gtrsim 5$. We find that spin cat states are not significantly Wigner-negative relative to their Dicke state counterparts of equal dimension. We also find, in contrast to several entanglement measures, that the most Wigner-negative Dicke basis element is spin-dependent, and not the equatorial state $| j,0 \rangle$ (or $|j,\pm 1/2 \rangle$ for half-integer spins). These results underscore the influence that dynamical symmetry has on nonclassicality, and suggest a guiding perspective for finding novel quantum computational applications.
