Phase-Programmable Gaussian Boson Sampling Using Stimulated Squeezed Light

TLDR

The study develops a high‑brightness, scalable quantum light source based on stimulated emission of squeezed photons, achieving near‑unity purity and efficiency. The system implements phase‑programmable Gaussian boson sampling by tuning the phase of input squeezed states and validates samples via subsystem inference to exclude distinguishable‑photon and thermal‑state hypotheses. The experiment achieves phase‑programmable GBS with up to 113 photon events, passes nonclassicality tests, exhibits high‑order correlations, and scales to a Hilbert space of ~10^43 with a sampling rate ~10^24 times faster than classical brute‑force simulation.

Abstract

We report phase-programmable Gaussian boson sampling (GBS) which produces up to 113 photon detection events out of a 144-mode photonic circuit. A new high-brightness and scalable quantum light source is developed, exploring the idea of stimulated emission of squeezed photons, which has simultaneously near-unity purity and efficiency. This GBS is programmable by tuning the phase of the input squeezed states. The obtained samples are efficiently validated by inferring from computationally friendly subsystems, which rules out hypotheses including distinguishable photons and thermal states. We show that our GBS experiment passes a nonclassicality test based on inequality constraints, and we reveal nontrivial genuine high-order correlations in the GBS samples, which are evidence of robustness against possible classical simulation schemes. This photonic quantum computer, Jiuzhang 2.0, yields a Hilbert space dimension up to ∼10^{43}, and a sampling rate ∼10^{24} faster than using brute-force simulation on classical supercomputers.