Abstract
In the early 1990′s, A. Elitzur and L. Vaidman proposed an interaction-free measurement (IFM) that allows researchers to find infinitely fragile objects without destroying them. But the Elitzur-Vaidman IFM has been used only to determine the position of opaque objects. We propose a non-trivial extension of such a technique with matter waves, which allows measurement of classical fields. And we show severe limitations when we talk about gravitational fields.
