|Title||Device-independent Randomness Expansion with Entangled Photons|
|Publication Type||Journal Article|
|Year of Publication||2021|
|Authors||Shalm, LK, Zhang, Y, Bienfang, JC, Schlager, C, Stevens, MJ, Mazurek, MD, Abellán, C, Amaya, W, Mitchell, MW, Alhejji, MA, Fu, H, Ornstein, J, Mirin, RP, Nam, SWoo, Knill, E|
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.