2025/03/17 by Drummond, Peter D., Dellios, Alexander S., Reid, Margaret D.
#Computational Physics (physics.comp-ph) #FOS: Physical sciences #Mathematical Physics (math-ph) #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.2503.12749
We introduce matrix quantum phase-space distributions. These extend the idea of a quantum phase-space representation via projections onto a density matrix of global symmetry variables. The method is applied to verification of low-loss Gaussian boson sampling (GBS) quantum computational advantage experiments with up to 10,000 modes, where classically generating photon-number counts is exponentially hard. We demonstrate improvements in sampling error by a factor of 1000 or more compared to unprojected methods, which are infeasible for such cases.