Professor Herman Batelaan
Department of Physics and Astronomy, University of Nebraska-Lincoln
The Kapitza-Dirac effect and other mysteries in quantum mechanics. Perhaps you have sometimes wondered why light that reflects from a CD disk is so colorful. This effect is caused by light waves of different color diffracting to separate angles from the small regular patterns on the CD surface. In quantum mechanics we learn that matter also behaves like waves just as light does. From this we may expect that matter can also diffract from a regular structure. We showed this effect by diffracting electrons from the periodic structure of light itself. This solved for the first time a 70 year old problem first proposed by Kapitza and Dirac. However, the story is not finished. We will not only show our results but also discuss an often not recognized problem: still nobody understands what deflects the electrons. |