A simplified scheme for testing complementarity and realizing quantum eraser

We propose a simple method to test Bohr complementarity in the context of c avity QED. When an atom is sent through two resonant classical fields, the probability of finding the atom in definite states exhibit interference fri nges. Replacing the first classical field with a quantized cavity field, th e interference is destroyed since the which-path information for the atom r eaching a definite state is recorded in the cavity. The associated quantum eraser can also be realized. (C) 2000 Elsevier Science B.V. All rights rese rved.