发表机构
S. N. Bose National Centre for Basic Sciences（S.N. 玻色基础科学国家中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过关联方的局部测量，可将经典约化态远程激活为非经典条件态，并解锁异常弱值及Wigner负性，识别测量诱导操控为远程激活非经典性的操作资源。
AI 中文摘要
非经典性，通过准概率分布（如Wigner分布和Kirkwood-Dirac分布）的非正性来定义，是量子优势的关键基础。我们证明它可以被远程激活：仅由关联伙伴的局部测量，就能将约化态为经典的一方驱动到真正非经典的的条件态。对于两量子比特系统，我们得到了最大单分支效应的闭式表达式，以及在最佳两结果投影测量下的概率加权平均的闭式表达式，后者在共享态无局部偏差时被证明在所有测量中是最优的。被操控方的局部噪声，相对于其自身噪声更新的参考基进行评估，当噪声非幺正且与该方的轴不对齐时，可以增强效应，而任何幺正信道则永远无助于增强。我们展示了这种非经典性，对于相同的参考可观测量，能够解锁在任意后选择下未操控态无法获得的异常弱值。一个精确可解的混合量子比特-振荡器模型表明，同样的机制会产生Wigner负性。这些结果将测量诱导的操控识别为远程激活非经典性的操作资源。
英文摘要
Nonclassicality, defined through nonpositivity of quasiprobability distributions such as the Wigner and Kirkwood-Dirac distributions, underlies key quantum advantages. We show that it can be remotely activated: local measurements by a correlated partner alone can drive a party whose reduced state is classical into a genuinely nonclassical conditional state. For two-qubit systems we obtain closed forms for the maximal single-branch effect and for its probability-weighted average under the best two-outcome projective measurement, the latter proven optimal over all measurements when the shared state carries no local bias. Local noise on the steered party, evaluated relative to its own noise-updated reference basis, can enhance the effect when non-unital and misaligned with that party's axis, whereas no unital channel ever helps. This nonclassicality is shown to unlock, for the same reference observable, anomalous weak values unavailable to the unsteered state under arbitrary postselection. An exactly solvable hybrid qubit-oscillator model shows the same mechanism generates Wigner negativity. These results identify measurement-induced steering as an operational resource for remotely activating nonclassicality.
Comments26 pages
