# Coherence as a resource for source-independent quantum random-number generation

## TL;DR

This paper introduces a coherence-based framework for source-independent quantum random number generation, enabling higher randomness rates without full state tomography by using coherence witnesses.

## Contribution

It formalizes source-independent quantum randomness via coherence, introduces nonlinear coherence witnesses, and demonstrates improved randomness generation rates over existing methods.

## Key findings

- Coherence witnesses can estimate source coherence without full tomography.
- The proposed scheme achieves higher randomness rates than uncertainty-relation-based methods.
- Existing schemes are special cases within the coherence framework.

## Abstract

Measuring quantum states provides means to generate genuine random numbers. It has been shown that genuine randomness can be obtained even with an uncharacterized quantum source. In this work, we propose a framework that formalizes the idea of realizing source-independent quantum random number generation via measuring coherence. Without full state tomography, the coherence of the source can be estimated by coherence witnesses. The existing uncertainty-relation-based schemes can be treated as special cases under the coherence framework, as we design a nonlinear coherence witness that can essentially yield the same results. Meanwhile, we propose a source-independent random number generation scheme, which can achieve a higher randomness generation rate than the uncertainty-relation-based ones.