Better Randomness with Single Photons

TL;DR

This paper demonstrates that single photon sources generate more true randomness than lasers, highlighting their advantages for quantum random number generation and potential applications in microscopy and sensing.

Contribution

It provides a comparative analysis showing the superiority of single photon sources over lasers in generating true quantum randomness.

Findings

Single photon sources produce more randomness than lasers.

Single photons offer a provably true source of randomness.

Advantages extend to microscopy and sensing applications.

Abstract

Randomness is one of the most important resources in modern information science, since encryption founds upon the trust in random numbers. Since it is impossible to prove if an existing random bit string is truly random, it is relevant that they be generated in a trust worthy process. This requires specialized hardware for random numbers, for example a die or a tossed coin. But when all input parameters are known, their outcome might still be predicted. A quantum mechanical superposition allows for provably true random bit generation. In the past decade many quantum random number generators (QRNGs) were realized. A photonic implementation is described as a photon which impinges on a beam splitter, but such a protocol is rarely realized with non-classical light or anti-bunched single photons. Instead, laser sources or light emitting diodes are used. Here we analyze the difference in generating a true random bit string with a laser and with anti-bunched light. We show that a single photon source provides more randomness than even a brighter laser. This gain of usable entropy proves the advantages of true single photons versus coherent input states of light in an experimental implementation. The underlying advantage can be adapted to microscopy and sensing.