Quantum Entanglement of Monochromatic and Non-Monochromatic Photons on a Waveguide Beam Splitter

Entropy (Basel). 2021 Dec 27;24(1):49. doi: 10.3390/e24010049.

Abstract

It is well known that the waveguide beam splitter can be used as a source for the quantum entanglement of photons. The analysis of such quantum entanglement is a difficult problem even for monochromatic photons, since the system under study is multiparametric. This paper will show that quantum entanglement can be represented in a simple form not only for monochromatic photons but also for non-monochromatic ones. It will be shown that quantum entanglement for non-monochromatic photons can be very different from monochromatic photons, which can be used to create large quantum entanglement.

Keywords: monochromatic photons; nonmonochromatic photons; quantum entanglement; reflection coefficient; von Neumann entropy; waveguide beam splitter.