With the growing availability of experimental loophole-free Bell tests, it has become possible to implement a new class of device-independent random number generators whose output can be certified to be uniformly random without requiring a detailed model of the quantum devices used. However, all of these experiments require many input bits in order to certify a small number of output bits, and it is an outstanding challenge to develop a system that generates more randomness than is used. Here, we devise a device-independent spot-checking protocol which uses only uniform bits as input. Implemented with a photonic loophole-free Bell test, we can produce 24% more certified output bits (1,181,264,237) than consumed input bits (953,301,640), which is 5 orders of magnitude more efficient than our previous work [arXiv:1812.07786]. The experiment ran for 91.0 hours, creating randomness at an average rate of 3606 bits/s with a soundness error bounded by 5.7×10−7 in the presence of classical side information. Our system will allow for greater trust in public sources of randomness, such as randomness beacons, and the protocols may one day enable high-quality sources of private randomness as the device footprint shrinks.

%B Nat. Phys. %8 01/28/2021 %G eng %U https://arxiv.org/abs/1912.11158 %R https://doi.org/10.1038/s41567-020-01153-4 %0 Journal Article %J Phys. Rev. Lett. %D 2020 %T Experimental Low-Latency Device-Independent Quantum Randomness %A Yanbao Zhang %A Lynden K. Shalm %A Joshua C. Bienfang %A Martin J. Stevens %A Michael D. Mazurek %A Sae Woo Nam %A Carlos Abellán %A Waldimar Amaya %A Morgan W. Mitchell %A Honghao Fu %A Carl Miller %A Alan Mink %A Emanuel Knill %XApplications of randomness such as private key generation and public randomness beacons require small blocks of certified random bits on demand. Device-independent quantum random number generators can produce such random bits, but existing quantum-proof protocols and loophole-free implementations suffer from high latency, requiring many hours to produce any random bits. We demonstrate device-independent quantum randomness generation from a loophole-free Bell test with a more efficient quantum-proof protocol, obtaining multiple blocks of 512 bits with an average experiment time of less than 5 min per block and with certified error bounded by 2−64≈5.42×10−20.

%B Phys. Rev. Lett. %V 124 %8 12/24/2019 %G eng %U https://arxiv.org/abs/1812.07786 %N 010505 %R https://doi.org/10.1103/PhysRevLett.124.010505