TY - JOUR T1 - Device-independent Randomness Expansion with Entangled Photons JF - Nat. Phys. Y1 - 2021 A1 - Lynden K. Shalm A1 - Yanbao Zhang A1 - Joshua C. Bienfang A1 - Collin Schlager A1 - Martin J. Stevens A1 - Michael D. Mazurek A1 - Carlos Abellán A1 - Waldimar Amaya A1 - Morgan W. Mitchell A1 - Mohammad A. Alhejji A1 - Honghao Fu A1 - Joel Ornstein A1 - Richard P. Mirin A1 - Sae Woo Nam A1 - Emanuel Knill AB -

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.

UR - https://arxiv.org/abs/1912.11158 U5 - https://doi.org/10.1038/s41567-020-01153-4 ER - TY - JOUR T1 - Experimental Low-Latency Device-Independent Quantum Randomness JF - Phys. Rev. Lett. Y1 - 2020 A1 - Yanbao Zhang A1 - Lynden K. Shalm A1 - Joshua C. Bienfang A1 - Martin J. Stevens A1 - Michael D. Mazurek A1 - Sae Woo Nam A1 - Carlos Abellán A1 - Waldimar Amaya A1 - Morgan W. Mitchell A1 - Honghao Fu A1 - Carl Miller A1 - Alan Mink A1 - Emanuel Knill AB -

Applications 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.

VL - 124 UR - https://arxiv.org/abs/1812.07786 CP - 010505 U5 - https://doi.org/10.1103/PhysRevLett.124.010505 ER -