  We discuss a discrete-event simulation approach, which has been shown to give
a unified cause-and-effect description of many quantum optics and
single-neutron interferometry experiments. The event-based simulation algorithm
does not require the knowledge of the solution of a wave equation of the whole
system, yet reproduces the corresponding statistical distributions by
generating detection events one-by-one. It is showm that single-particle
interference and entanglement, two important quantum phenomena, emerge via
information exchange between individual particles and devices such as beam
splitters, polarizers and detectors. We demonstrate this by reproducing the
results of several single-neutron interferometry experiments, including one
that demonstrates interference and one that demonstrates the violation of a
Bell-type inequality. We also present event-based simulation results of a
single neutron experiment designed to test the validity of Ozawa's universally
valid error-disturbance relation, an uncertainty relation derived using the
theory of general quantum measurements.

Quantum Physics