# Experimental Gaussian Boson Sampling

## TL;DR

This paper reports the first experimental demonstration of Gaussian Boson Sampling using squeezed states, achieving high photon indistinguishability, increased sampling rates, and demonstrating quantum speed-up on an NP-hard problem.

## Contribution

It presents the first experimental implementation of GBS with high efficiency and speed, validating its potential for solving classically hard problems.

## Key findings

- Achieved 3-, 4-, and 5-photon GBS with high sampling rates
- Demonstrated quantum speed-up on an NP-hard optimization problem
- Sampling rates exceeded previous experiments by over 4 times

## Abstract

Gaussian Boson sampling (GBS) provides a highly efficient approach to make use of squeezed states from parametric down-conversion to solve a classically hard-to-solve sampling problem. The GBS protocol not only significantly enhances the photon generation probability, compared to standard boson sampling with single photon Fock states, but also links to potential applications such as dense subgraph problems and molecular vibronic spectra. Here, we report the first experimental demonstration of GBS using squeezed-state sources with simultaneously high photon indistinguishability and collection efficiency. We implement and validate 3-, 4- and 5-photon GBS with high sampling rates of 832 kHz, 163 kHz and 23 kHz, respectively, which is more than 4.4, 12.0, and 29.5 times faster than the previous experiments. Further, we observe a quantum speed-up on a NP-hard optimization problem when comparing with simulated thermal sampler and uniform sampler.

---
Source: https://tomesphere.com/paper/1905.00170