Boson sampling with 20 input photons in 60-mode interferometers at $10^{14}$ state spaces

TL;DR

This paper demonstrates a large-scale boson sampling experiment with 20 photons in a 60-mode interferometer, achieving a Hilbert space size of 10^14 and validating quantum advantage over classical methods.

Contribution

The authors developed high-quality solid-state single-photon sources and integrated ultra-low-loss 3D optical circuits for large-scale boson sampling experiments.

Findings

Successfully sampled from a 10^14-dimensional Hilbert space

Validated quantum sampling with 99.9% confidence

Achieved the largest boson sampling experiment to date

Abstract

Quantum computing experiments are moving into a new realm of increasing size and complexity, with the short-term goal of demonstrating an advantage over classical computers. Boson sampling is a promising platform for such a goal, however, the number of involved single photons was up to five so far, limiting these small-scale implementations to a proof-of-principle stage. Here, we develop solid-state sources of highly efficient, pure and indistinguishable single photons, and 3D integration of ultra-low-loss optical circuits. We perform an experiment with 20 single photons fed into a 60-mode interferometer, and, in its output, sample over Hilbert spaces with a size of $10^{14}$ $-$over ten orders of magnitude larger than all previous experiments. The results are validated against distinguishable samplers and uniform samplers with a confidence level of 99.9%.