arXiv:1208.1029

A Note Concerning von Neumann Projector Measurement Pointer States, Weak Values, and Interference

Allen Parks, John Edward Gray

Published Aug 5, 2012• 1 citation

Abstract

It is well known that the pointer state |Φ> resulting from the von Neumann measurement of a projection operator A performed upon an ensemble of quantum systems in the preselected state |ψ> depends upon A|ψ>. Here it is shown that the pointer state |Ψ> obtained from such a measurement performed upon an ensemble that is also postselected depends upon the weak value of A - regardless of the measurement interaction strength. It is also found that, while the spatial distribution of |Ψ> exhibits interference, the idempotency of A prohibits interference in that of |Φ>. This is explained in terms of welcher Weg information.

DOI: 10.48550/arxiv.1208.1029

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