1110.6056 (Jeffrey H. Shapiro)

Comment on `Simulation of Bell states with incoherent thermal light'    [PDF]

Jeffrey H. Shapiro

Recently, Chen \em et al\rm.\ [New J. Phys. {\bf 13} (2011) 083018] presented
experimental results, accompanied by quantum-mechanical analysis, showing that
the quantum interference behavior of Bell states could be simulated in a
modified Mach-Zehnder interferometer whose inputs are pseudothermal light beams
obtained by passing laser light through a rotating ground-glass diffuser. Their
experiments and their theory presumed low-flux operation in which the simulated
quantum interference is observed via photon-coincidence counting. We first show
that the Chen \em et al\rm.\ photon-coincidence counting experiments can be
fully explained with semiclassical photodetection theory, in which light is
taken to be a classical electromagnetic wave, and the discreteness of the
electron charge leads to shot noise as the fundamental photodetection noise. We
then use semiclassical photodetection theory to show that the \em same\rm\
simulated quantum interference pattern can be observed in high-flux operation,
when photocurrent cross-correlation is used instead of photon-coincidence
counting.

View original: http://arxiv.org/abs/1110.6056