Quantum random number generation enhanced by weak-coherent states interference

TL;DR

This paper introduces a quantum random number generation method using interference of weak-coherent states at a beam splitter, demonstrating improved randomness and efficiency over traditional single-state approaches.

Contribution

The authors propose and experimentally validate a novel quantum RNG technique leveraging weak-coherent state interference, achieving up to 32% improvement in random bit generation efficiency.

Findings

Interference reduces coincident counts, increasing valid output probability.

Experimental results match simulations, confirming theoretical predictions.

Generated bit strings pass standard randomness tests.

Abstract

We propose and demonstrate a technique for quantum random number generation based on the random population of the output spatial modes of a beam splitter when both inputs are simultaneously fed with indistinguishable weak coherent states. We simulate and experimentally validate the probability of generation of random bits as a function of the average photon number per input, and compare it to the traditional approach of a single weak coherent state transmitted through a beam-splitter, showing an improvement of up to 32\%. The ensuing interference phenomenon reduces the probability of coincident counts between the detectors associated with bits 0 and 1, thus increasing the probability of occurrence of a valid output. A long bit string is assessed by a standard randomness test suite with good confidence. Our proposal can be easily implemented and opens attractive performance gains without a significant trade-off.