  We propose a scheme for linear optical quantum Fredkin gate based on the
combination of recently experimentally demonstrated linear optical partial SWAP
gate and controlled-Z gates. Both heralded gate and simplified postselected
gate operating in the coincidence basis are designed. The suggested setups have
a simple structure and require stabilization of only a single Mach-Zehnder
interferometer. A proof-of-principle experimental demonstration of the
postselected Fredkin gate appears to be feasible and within the reach of
current technology.
