Simulating complex networks in phase space: Gaussian boson sampling

Abstract

Phase-space representations are vital in simulating exponentially complex quantum systems. Here these are demonstrated for Gaussian quantum states in a photonic network. We show that output counts can be efficiently simulated, providing a means for verifying Gaussian boson sampling (GBS) quantum computers. Our numerical results generally agree with recent 100 channel experimental data, giving evidence for additional decoherence. We also show how to simulate genuine multipartite entanglement.