  Over the last several decades, quantum entanglement has been intensively
studied for potential applications in quantum information science. Although
intensive studies have progressed for nonlocal correlation, fundamental
understanding of entanglement itself is still limited. Here, the quantum
feature of anticorrelation, the so-called HOM dip, based on probabilistic
entangled photon pairs is analyzed for its fundamental physics and compared
with a new method of on-demand entangled photon pair generations using coherent
light. The fundamental physics why there is no g^((1)) correlation in HOM dip
measurements is answered, and new coherence quantum physics is proposed for
macroscopic quantum entanglement generations.
