How Quantum Is Light? Concepts, Measures, and Applications of Optical Quantumness

Year: 2026

Type: preprint

Abstract: Quantum states are ultimately responsible for numerous counterintuitive phenomena that defy classical intuition. As the development of quantum technologies accelerates, our ability to harness these quantum resources becomes essential. This review addresses a fundamental question. How do we quantify the quantumness of a state, and which specific traits distinguish it from its classical counterparts? We examine quantumness through both theoretical and operational lenses, providing a clear framework for state characterization. Ultimately, we demonstrate that certifying quantumness is not just a theoretical exercise. It is a practical necessity for identifying, and realizing quantum advantage in real-world applications.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2610.25894

Authors: Bose, Soumyakanti, Kwon, Hyukjoon, Teo, Yong Siah, Jeong, Hyunseok, Sánchez-Soto, Luis L.

Institutions: Seoul National University, SRM University, Andhra Pradesh, Korea Institute for Advanced Study, Sejong University

Language: English

Topic: Quantum Information and Cryptography

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funders: Sejong University, Seoul National University, National Research Foundation of Korea, Ministry of Science and ICT, South Korea, Institute for Information and Communications Technology Promotion, Agencia Estatal de Investigación

OpenAlex ID: W7223068470