Randomness in quantum random number generator from vacuum fluctuations with source-device-independence

TL;DR

This paper presents an experimental implementation of a source-device independent quantum random number generator utilizing vacuum fluctuations and homodyne detection, analyzing optimal parameters for maximum randomness extraction.

Contribution

The study demonstrates a method to optimize a quantum random number generator based on vacuum fluctuations with concurrent quadrature measurements for improved semi-device independence.

Findings

Optimal experimental parameters for the generator are characterized.

Randomness is quantified using Shannon and von Neumann entropy.

Concurrent quadrature measurement enhances source-device independence.

Abstract

The application for random numbers is ubiquitous. We experimentally build a well-studied quantum random number generator from homodyne measurements on the quadrature of the vacuum fluctuations. Semi-device-independence in this random number generator is usually obtained using phase modulators to shift the phase of the laser and obtain random sampling from both X and P quadrature measurements of the vacuum state in previous implementations. We characterize the experimental parameters for optimal performance of this source-device independent quantum random number generator by measuring the two quadratures concurrently using two homodyne detectors. We also study the influence of these parameters on randomness, which can be extracted based on Shannon entropy and von Neumann entropy, which correspond to an eavesdropper listening to classical and quantum side information, respectively.