Benchmarking Gaussian and non-Gaussian input states with a hybrid sampling platform

TL;DR

This paper introduces the Paderborn Quantum Sampler (PaQS), a hybrid platform for benchmarking Gaussian and non-Gaussian input states in quantum sampling, demonstrating performance advantages of non-Gaussian states.

Contribution

The authors develop a versatile platform enabling direct comparison of Gaussian and non-Gaussian states in quantum sampling experiments with certification of quantum advantage.

Findings

Non-Gaussian states show clear performance gains in sampling tasks.

The platform performs experiments with eight input states in a 12-mode interferometer.

Semi-device-independent certification confirms quantum advantage.

Abstract

The original boson sampling paradigm-consisting of multiple single-photon input states, a large interferometer, and multi-channel click detection-was originally proposed as a photonic route to quantum computational advantage. Its non-Gaussian resources, essential for outperforming any classical system, are provided by single-photon inputs and click detection. Yet the drive toward larger experiments has led to the replacement of experimentally demanding single-photon sources with Gaussian states, thereby diminishing the available non-Gaussianity-a critical quantum resource. As the community broadens its focus from the initial sampling task to possible real-world applications, it becomes crucial to quantify the performance cost associated with reducing non-Gaussian resources and to benchmark sampling platforms that employ different input states. To address this need, we introduce the Paderborn Quantum Sampler (PaQS), a hybrid platform capable of performing sampling experiments with eight Gaussian or non-Gaussian input states in a 12-mode interferometer within a single experimental run. This architecture enables direct, side-by-side benchmarking of distinct sampling regimes under otherwise identical conditions. By employing a semi-device-independent framework, offering certification that does not rely on prior knowledge of the interferometer or the input states, we verify that the observed data cannot be reproduced by any classical model-a prerequisite for demonstrating quantum advantage. Applying this framework, we observe clear performance gains arising from non-Gaussian input states.