Boosting Gaussian Boson Sampling using Optical Parametric Amplification Networks

TL;DR

This paper introduces an active optical network with parametric amplifiers to enhance Gaussian Boson Sampling, maintaining quantum advantage despite losses, and demonstrating improved entanglement scaling for photonic quantum computing.

Contribution

The paper proposes a novel OPA-based architecture that amplifies quantum correlations in GBS, preserving computational hardness under realistic loss conditions.

Findings

Entanglement scales linearly with OPA gain and network depth in lossless scenarios.

Entanglement maintains linear scaling with the number of modes under realistic loss.

OPA-boosted GBS remains computationally hard in noisy environments.

Abstract

Gaussian Boson Sampling (GBS) provides a route toward demonstrating quantum computational advantage. However, optical loss, which reduces the entanglement in the system, can render GBS results classically simulable. We propose a nonlinear photonic architecture based on optical parametric amplifiers (OPAs) arranged in an interferometer network. This active configuration amplifies quantum correlations within the circuit while preserving the #P-hard Hafnian structure of the output probabilities. Using logarithmic negativity, we numerically show that entanglement scales linearly with both the OPA gain and network depth in the lossless limit, and maintains linear scaling with the number of modes under realistic loss rate. These scaling behaviors suggest that classical simulation in lossy scenarios remains computationally intractable. Our results demonstrate that OPA-boosted GBS preserves computational hardness in noisy environments, offering a more effective implementations of near-term photonic quantum computers.