Toward quantum computational supremacy of boson sampling with random overlap in the photonic spectra
Simon Laibacher, Vincenzo Tamma · arXiv (Cornell University) · 2018
Multiphoton interference is at the very heart of quantum foundations and applications in quantum sensing and information processing. In particular, boson sampling experiments have the potential to demonstrate quantum computational supremacy while only relying on multiphoton interference in linear optical interferometers. However, scalable experiments are challenged by the need to generate the same temporal and frequency spectra for a large number $N$ of single photons in each experimental sample. Here, we employ sampling correlation measurements in the photonic inner modes, time and frequency, at the interferometer input and output to ensure the occurrence of multiphoton interference even with input photons with random overlap in their input spectra from one sample to another. This allows us to substantially enhance the probability to successfully generate a sample and therefore the experimental scalability of boson sampling schemes. Furthermore, we show that it is possible, in principle, to approach deterministic boson sampling with a number of probabilistic sources which is only slightly larger than $N$. This is achieved by combining sampling in the photonic inner modes with sampling over the number of input photons per port. Therefore, these results provide an exciting route toward future demonstrations of quantum computational supremacy with scalable experimental resources.