A novel computational approach towards the certification of large-scale boson sampling

Robert Keil, Christoph Dittel, Thomas Kauten +6 more

Raphael A. Abrahão, Arman Mansouri, Austin P. Lund

A universal quantum computer of large scale is not available yet, however, intermediate models of quantum computation would still permit demonstrations of a quantum computational advantage over classical computing and could challenge the extended Church-Turing thesis. One of these models based on single photons interacting via linear optics is called boson sampling. Although boson sampling was demonstrated and the threshold to claim quantum computational advantage was achieved, the question of how to scale up boson sampling experiments remains. To make progress with this problem, here we present a practically achievable pathway to scale boson sampling experiments by combining continuous-variable quantum information and temporal encoding. We propose the combination of switchable dual-homodyne and single-photon detections, the temporal loop technique, and scattershot-based boson sampling. We detail the required assumptions for concluding computational hardness for this configuration. Furthermore, this particular combination of techniques moves towards an efficient scaling and certification of boson sampling, all in a single experimental setup.

Verena Yacoub, Yoann Piétri, Damian Markham +2 more

Youri Cherif, Verena Yacoub, Ulysse Chabaud +2 more

Raphael A. Abrahão, Austin P. Lund

A universal quantum computer of moderate scale is not available yet, however intermediate models of quantum computation would still permit demonstrations of a quantum computational advantage over classical computing and could challenge the Extended Church-Turing Thesis. One of these models based on single photons interacting via linear optics is called Boson Sampling. Although Boson Sampling was demonstrated and the threshold to claim quantum computational advantage was achieved, the question on how to scale up Boson Sampling experiments remains. To make progress with this problem, here we present a practically achievable pathway to scale Boson Sampling experiments with current technologies by combining continuous-variables quantum information and temporal encoding. We propose the use of switchable dual-homodyne and single-photon detections, the temporal loop technique and scattershot based Boson Sampling. This proposal gives details as to what the required assumptions are and a pathway for scaling Boson Sampling experiments. Furthermore, this particular combination of techniques permits a single efficient implementation of Boson Sampling and efficient certification in a single experimental setup.

Kai Liu, Austin P. Lund, Yongjian Gu +1 more

Boson sampling can provide strong evidence that the computational power of a quantum computer outperforms a classical one via currently feasible linear optics experiments. However, how to identify an actual boson sampling device against any classical computing imposters is an ambiguous problem due to the computational complexity class in which boson sampling lies. The certification protocol based on bosonic bunching fails to rule out the so-called mean-field sampling. We propose a certification scheme to distinguish the boson sampling from the mean-field sampling for any random scattering matrices chosen via the Harr-measure. We numerically analyze our scheme and the influence of imperfect input states caused by non-simultaneous arrival photons.