Single photon experiments for quantum applications: quantum sensing, quantum machine learning, and quantum decision theory

Abstract

Single photon source is a representative quantum light source. Over 100 years of research into photons expanded our understanding of optics. The non-classical features of photon have presented quantum advantage beyond classical optics in a wide range of areas. Now, the advances in technology to deal with the single photon have brought a variety of the applications in the quantum optics. In this thesis, I studied how the single photon source can be utilized in the following application fields: quantum machine learning, quantum decision theory, and quantum optical sensing. I show, theoretically and experimentally, what and how the quantum nature of single photon contributes to any possible quantum advantage in above fields. I focus on the following two distinct quantum features of the single photon. First is quantum superposition. Simultaneous operations allowed by the quantum superposition enable the efficient quantum operation to surpass the classical counterpart. The quantum advantages related to the quantum superposition are studied for the machine learning and the quantum decision theory. Second is anti-bunching, representing a more silent distribution of single photon source. This can provide a less noise than the classical light source in the optical sensing. It is expected that the development of the quantum technology brings the quantum advantage in a wide range of applications.