Directly Observing Momentum Transfer in Twin-Slit "Which-Way" Experiments
Abstract
Is the destruction of interference by a which-way measurement due to a random momentum transfer $\wp\agt\hbar/s$, with
s
the slit separation? The weak-valued probability distribution
P
wv
(℘)
, which is {\em directly observable}, provides a subtle answer.
P
wv
(℘)
cannot have support on the interval
[−ℏ/s,ℏ/s]
. Nevertheless, its moments can be identically zero.