MHz-rate semi-device-independent quantum random number generators based on unambiguous state discrimination

TL;DR

This paper introduces a semi-device-independent quantum random number generator using unambiguous state discrimination, achieving MHz rates with practical optical implementation and real-time entropy estimation.

Contribution

The paper presents a novel semi-device-independent QRNG protocol based on USD, demonstrating high-speed optical implementation and real-time entropy estimation.

Findings

Achieved 16.5 Mbit/s random number generation rate.

Implemented a practical optical setup for USD-based QRNG.

Provided a method for real-time entropy estimation.

Abstract

An approach to quantum random number generation based on unambiguous quantum state discrimination (USD) is developed. We consider a prepare-and-measure protocol, where two non-orthogonal quantum states can be prepared, and a measurement device aims at unambiguously discriminating between them. Because the states are non-orthogonal, this necessarily leads to a minimal rate of inconclusive events whose occurrence must be genuinely random and which provide the randomness source that we exploit. Our protocol is semi-device-independent in the sense that the output entropy can be lower bounded based on experimental data and few general assumptions about the setup alone. It is also practically relevant, which we demonstrate by realising a simple optical implementation achieving rates of 16.5 Mbits/s. Combining ease of implementation, high rate, and real-time entropy estimation, our protocol represents a promising approach intermediate between fully device-independent protocols and commercial QRNGs.