Deploying single photons towards experimental tests of Complementarity, Quantum Key Distribution, and Macrorealism

Abstract

Single photon is one of the most valuable resources in quantum science and technology. As being the single particle of light, it shows the behaviour of true quantumness, which is used in various quantum mechanical applications, including quantum information, communication, metrology, etc. There are various ways to prepare single photons [P4], among which spontaneous parametric down-conversion (SPDC) is the most popular one. In the SPDC process, single photon pairs are generated, where detection of one photon in the pair heralds the other photon of the same pair. In this thesis work, single photons generated from the SPDC process have been used in different experiments covering quantum fundamentals as well as technologies.