Single Photon Randomness based on a Defect Center in Diamond

TL;DR

This paper demonstrates a quantum random number generator using single photons emitted from a defect center in diamond, leveraging quantum superposition and vacuum fluctuations to produce true randomness under ambient conditions.

Contribution

It introduces a stable, ambient-condition quantum random number generator based on diamond defect centers, with analysis of photon emission and entropy estimation.

Findings

Achieved continuous 24/7 operation of the generator.

Verified the quantum nature of the photon source via anti-bunching.

Discussed methods to suppress technical noise and bias.

Abstract

The prototype of a quantum random number generator is a single photon which impinges onto a beam splitter and is then detected by single photon detectors at one of the two output paths. Prior to detection, the photon is in a quantum mechanical superposition state of the two possible outcomes with - ideally - equal amplitudes until its position is determined by measurement. When the two output modes are observed by a single photon detector, the generated clicks can be interpreted as ones and zeros - and a raw random bit stream is obtained. Here we implement such a random bit generator based on single photons from a defect center in diamond. We investigate the single photon emission of the defect center by an anti-bunching measurement. This certifies the "quantumness" of the supplied photonic input state, while the random "decision" is still based on the vacuum fluctuations at the open port of the beam-splitter. Technical limitations, such as intensity fluctuations, mechanical drift, and bias are discussed. A number of ways to suppress such unwanted effects, and an a priori entropy estimation are presented. The single photon nature allows for a characterization of the non-classicality of the source, and allows to determine a background fraction. Due to the NV-center's superior stability and optical properties, we can operate the generator under ambient conditions around the clock. We present a true 24/7 operation of the implemented random bit generator.