Generation of maximally entangled photonic states with a quantum-optical Fredkin gate - art. no. 063814

When a quantum-optical Fredkin gate is embedded into a Mach-Zehnder interfe rometer, state reduction techniques permit the generation of maximally enta ngled states of the radiation field when Fock states are input to the devic e. These exactly reach the Heisenberg limit of phase sensitivity. We invest igate the consequences of injecting more general states. and particularly c oherent states, into the apparatus, Applications to interferometry and phot olithography are discussed.