The Quantum Delayed Choice Experiment Revisited

The Mach–Zehnder interferometer is a particularly simple device for demonstrating the wave-particle duality. This duality is particularly exhibited in the quantum delayed choice experiment where one realizes a superposition of wave- and particle-like behaviors. Considering this experiment as a generalized measurement described by a positive operator–valued measure (POVM), it realizes a joint measurement of path and interference obeying some duality relations.