Robust amplification of Santha-Vazirani sources with three devices

TL;DR

This paper introduces a quantum-based randomness amplification protocol using Bell experiments, capable of converting arbitrarily weak randomness into stronger randomness with finite time, by identifying a Bell inequality suitable for this task.

Contribution

It presents a novel protocol for amplifying weak randomness leveraging quantum resources and Bell inequalities, with a detailed analysis of violation requirements.

Findings

Bell inequality can amplify arbitrarily weak randomness

The protocol requires a finite amount of time for amplification

A sufficient Bell violation is achievable below quantum limits

Abstract

We demonstrate that amplification of arbitrarily weak randomness is possible using quantum resources. We present a randomness amplification protocol that involves Bell experiments. We find a Bell inequality which can amplify arbitrarily weak randomness and give a detailed analysis of the protocol involving it. Our analysis includes finding a sufficient violation of Bell inequality as a function of the initial quality of randomness. It has a very important property that for any quality the required violation is strictly lower than possible to obtain using quantum resources. Among other things, it means that the protocol takes a finite amount of time to amplify arbitrarily weak randomness.