ar X iv : 0 90 8 . 00 35 v 1 [ qu an t - ph ] 3 A ug 2 00 9 1 What do quantum “ weak ” measurements actually measure ?
نویسنده
چکیده
A precise definition of “weak [quantum] measurements” and “weak value” (of a quantum observable) is offered, and simple finite dimensional examples are given showing that weak values are not unique and therefore probably do not correspond to any physical attribute of the system being “weakly” measured, contrary to impressions given by most of the literature on weak measurements. A possible mathematical error in the seminal paper introducing “weak values” is explicitly identified. A mathematically rigorous argument obtains results similar to, and more general than, the main result of that paper and concludes that even in the infinite-dimensional context of that paper, weak values are not unique. This implies that the “usual” formula for weak values is not universal, but can apply only to specific physical situations. The paper is written in a more pedagogical and informal style than is usual in the research literature in the hope that it might serve as an introduction to weak values.
منابع مشابه
ar X iv : 0 90 9 . 02 95 v 2 [ qu an t - ph ] 8 S ep 2 00 9 1 Quantum weak values are not unique What do they actually measure ?
Precise definitions of “weak [quantum] measurements” and “weak value” [of a quantum observable] are offered, which seem to capture the meaning of the often vague ways that these terms are used in the literature. Simple finite dimensional examples are given showing that weak values are not unique. They therefore cannot correspond to any physical attribute of the system being “weakly” measured, c...
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Precise definitions of “weak [quantum] measurements” and “weak value” [of a quantum observable] are offered, which seem to capture the meaning of the often vague ways that these terms are used in the literature. Simple finite dimensional examples are given showing that weak values are not unique. They therefore cannot correspond to any physical attribute of the system being “weakly” measured, c...
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تاریخ انتشار 2009