Towards quantum supremacy with lossy scattershot boson sampling

Abstract

Boson sampling represents a promising approach to obtain evidence of the supremacy of quantum systems as a resource for the solution of computational problems. The classical hardness of Boson Sampling has been related to the so called Permanent-of-Gaussians Conjecture and has been extended to some generalizations such as Scattershot Boson Sampling, approximate and lossy sampling under some reasonable constraints. However, it is still unclear how demanding these techniques are for a quantum experimental sampler. Starting from a state of the art analysis and taking account of the foreseeable practical limitations, we evaluate and discuss the bound for quantum supremacy for different recently proposed approaches, accordingly to today's best known classical simulators.

Quantum sampling problems, BosonSampling and quantum supremacy

“…36 Thus the major challenge to realising an intermediate optical quantum computer of this kind is the ability to efficiently (i.e., with very low loss and noise) implement a reconfigurable, universal linear optical network over hundreds to thousands of modes. 37 On-chip designs such as the 6 mode reconfigurable, universal circuit demonstrated by J. Carolan et al 38 are one of several promising ways forward. Another interesting approach is the reconfigurable timemultiplexed interferometer proposed by Motes et al 39 and recently implemented in free-space by Y.…”

Active demultiplexing of single photons from a solid‐state source

“…The proposed demultiplexing device is of general interest for any bright temporally distributed single‐photon source and provides a scalable approach for the realisation of multi‐photon sources of larger photon numbers. Our platform thus constitutes a very promising approach for scalable quantum photonics, in particular for protocols of intermediate—i.e., non universal—quantum computation, such as Boson Sampling , where, arguably, as few as seven photons from an actively demultiplexed quantum dot‐based source could finally demonstrate the quantum advantage over classical systems .…”

Classical boson sampling algorithms with superior performance to near-term experiments

“…Photon statistics are governed by intractable matrix functions, which suggests that sampling from the distribution obtained by injecting photons into a linear optical network could be solved more quickly by a photonic experiment than by a classical computer. The apparently low resource requirements for large boson sampling experiments have raised expectations of a near-term demonstration of quantum supremacy by boson sampling 7,8 . Here we present classical boson sampling algorithms and theoretical analyses of prospects for scaling boson sampling experiments, showing that near-term quantum supremacy via boson sampling is unlikely.…”