Quantum computational advantage using photons

TL;DR

This paper demonstrates a quantum computational advantage using Gaussian boson sampling with 50 squeezed states, a 100-mode interferometer, and 100 detectors, achieving a sampling rate vastly surpassing classical simulations.

Contribution

It presents an experimental realization of quantum advantage with high indistinguishability and large-scale optical setup, surpassing classical simulation capabilities.

Findings

Sampling rate 10^14 times faster than classical methods

Output state space dimension of 10^30

Validation against multiple classical hypotheses

Abstract

Gaussian boson sampling exploits squeezed states to provide a highly efficient way to demonstrate quantum computational advantage. We perform experiments with 50 input single-mode squeezed states with high indistinguishability and squeezing parameters, which are fed into a 100-mode ultralow-loss interferometer with full connectivity and random transformation, and sampled using 100 high-efficiency single-photon detectors. The whole optical set-up is phase-locked to maintain a high coherence between the superposition of all photon number states. We observe up to 76 output photon-clicks, which yield an output state space dimension of $10^{30}$ and a sampling rate that is $10^{14}$ faster than using the state-of-the-art simulation strategy and supercomputers. The obtained samples are validated against various hypotheses including using thermal states, distinguishable photons, and uniform distribution.