Experimental Randomness Amplification

Non-locality has emerged as a central resource for device-independent quantum information processing, enabling protocols such as quantum key distribution, certified randomness generation, and self-verification of untrusted devices. Despite rapid experimental progress, ensuring perfect input randomness remains an important open problem for non-locality-based algorithms. To address this challenge, we demonstrate device-independent randomness amplification, allowing generating stronger randomness from a weak input randomness resource–a task impossible in classical physics. Our implementation combines two recent developments: a theoretical randomness amplification protocol tailored to experimentally realizable devices requiring only a two-node system [1]; and the experimental progress enabling executing a loophole-free Bell test with superconducting circuits providing a unique combination high Bell pair generation rate and violation of the Bell inequality [2]. Looking forward, the combination of randomness amplification with quantum networks promises secure communication and computation under minimal assumptions [3], even when the available randomness is weak.

 

[1] Kessler et. al., IEEE Journal on Selected Areas in Information Theory 1, 568 (2020)

[2] Storz et. al., Nature 617, 265 (2023)

[3] Ekert et. al., Nature 507, 443 (2014)