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arXiv 0905.3810quant-ph
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弱值、“负概率”和不确定原理

Weak values, 'negative probability' and the uncertainty principle

D. Sokolovski

摘要:

量子跃迁可以看作是各种路径(例如费曼路径)之间干涉的结果,这些路径可以用变量$f$标记。试图确定f的值而不破坏通路之间的相干性会产生$\bar{f}$的弱值。我们表明$\bar{f}$是一个平均值,得到的振幅分布,可以在一般情况下,采取负值,按照不确定原理,不需要包含信息的实际范围内的值$f$,有助于过渡。我们还证明了这种交替分布的矩具有一些不寻常的性质,这可能会导致对弱测量结果的误解。我们提供了一个详细的分析,弱测量后选择和不后选择。例子包括双缝衍射实验、弱冯·诺依曼和类冯·诺依曼测量、弹性碰撞的穿越时间、相位时间、局部角动量(LAM)和{ \it Aharonov et al}的“三箱情况”

英文摘要:

A quantum transition can be seen as a result of interference between various pathways(e.g. Feynman paths) which can be labelled by a variable $f$. An attempt to determine the value of f without destroying the coherence between the pathways produces a weak value of $\bar{f}$. We show $\bar{f}$ to be an average obtained with amplitude distribution which can, in general, take negative values which, in accordance with the uncertainty principle, need not contain information about the actual range of the values $f$ which contribute to the transition. It is also demonstrated that the moments of such alternating distributions have a number of unusual properties which may lead to misinterpretation of the weak measurement results.We provide a detailed analysis of weak measurements with and without post-selection. Examples include the double slit diffraction experiment,weak von Neumann and von Neumann-like measurements, traversal time for an elastic collision, the phase time, the local angular momentum(LAM) and the 'three-box case' of {\it Aharonov et al}

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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