Figure 1

A

B

Thought experiment for a kicked double slit. (a) A coherent particle wave travels through the double slit to the screen where its probability distribution shows interference if no which-way information can be gained. Along path) the particle is deflected downward (upward), therefore measurement of the double-slit momentum for each particle should allow determination of their paths. Equivalently, the momentum transfer to the first slit could be measured as was originally proposed by Einstein [ 1 ]. (b) Two-dimensional version of the arrangement in (a). Momentum transfer from the projectile can cause a clockwise- or anticlockwise-rotation of the pinholes. (c) Experimental implementation of (b). Atoms collide with a HD molecule. Rutherford scattering at one of the molecular nuclei establishes the two interfering pathways. The scattered atom is observed in coincidence with the molecular fragments. In contrast to the macroscopic slit arrangement in (b) with the rotation axis located exactly in between the apertures, the unequal nuclear masses of our molecular microslits lead to a curving of the interference fringes. Reuse & Permissions