Quantum Random Number Generator (QRNG): Theoretical and Experimental Investigations

Abstract: Quantum Random Number Generators (QRNGs) emerged as a promising solution for generating truly random numbers. In the present article, we give an overview of QRNGs highlighting the merits and demerits of various strategies briefly. Then opting for the best-case scenario, we present the in-depth experimental explorations for building and characterizing QRNG using the homodyne detection technique to measure the quadrature amplitude of quantum vacuum fluctuations. Since entropy assessment plays a fundamental role in authenticating the true randomness, a comprehensive description of entropy and how it evaluates the quality of randomness of the source is illustrated. Our experimental setup, apart from the hardware, includes a diverse set of testing techniques including NIST statistical/entropy suites, Dieharder tests battery, and autocorrelation coefficient to verify the randomness and statistical properties of the generated random numbers. We believe that our experimental investigations provide a valuable resource for building QRNGs for a wide range of applications.