  Indistinguishability in quantum mechanics is an essential concept to
understanding mysterious quantum features such as self-interference of a single
photon and two-photon nonlocal correlation. Delayed-choice experiments are for
the cause-effect violation via post-measurements of photons in an
interferometric system. Recently, a macroscopic version of the delayed-choice
experiments has been demonstrated using the classical means of Poisson
distributed photons in a noninterfering Mach-Zehnder interferometer (NMZI).
Here, a coherence version of the nonlocal correlation is presented using the
wave nature of photons in space-like separated orthogonally polarized NMZIs.
For this, polarization-basis projections of the pair of NMZI output photons
onto a set of polarizers are measured coincidently, where each output photon
comprises orthogonal polarization bases. Because of the coherence feature of
the output photons via coincidence detection, a phase sensitive nonlocal
correlation is achieved. As a result, indistinguishability limited to a single
or entangled photon pairs needs to be reconsidered with basis (polarization)
randomness for the nonlocal correlation.
