  It is well known that in a two-slit interference experiment, if the
information, on which of the two paths the particle followed, is stored in a
quantum path detector, the interference is destroyed. However, in a setup where
this path information is "erased", the interference can reappear. Such a setup
is known as a quantum eraser. A generalization of quantum eraser to a
three-slit interference is theoretically analyzed. It is shown that three
complementary interference patterns can arise out of the quantum erasing
process.
