A Benchmark Test of Boson Sampling on Tianhe-2 Supercomputer

TL;DR

This paper benchmarks the classical simulation of boson sampling on the Tianhe-2 supercomputer, determining its capacity and limitations, and highlights a precision issue in one of the algorithms used.

Contribution

It provides the first large-scale simulation of boson sampling on a supercomputer, establishing an upper bound on classical simulation performance and identifying a precision problem in existing algorithms.

Findings

Tianhe-2 can simulate a 50-photon boson sampling in about 100 minutes.

The simulation used up to 312,000 CPU cores.

A precision issue was found in one permanent-computing algorithm.

Abstract

Boson sampling, thought to be intractable classically, can be solved by a quantum machine composed of merely generation, linear evolution and detection of single photons. Such an analog quantum computer for this specific problem provides a shortcut to boost the absolute computing power of quantum computers to beat classical ones. However, the capacity bound of classical computers for simulating boson sampling has not yet been identified. Here we simulate boson sampling on the Tianhe-2 supercomputer which occupied the first place in the world ranking six times from 2013 to 2016. We computed the permanent of the largest matrix using up to 312,000 CPU cores of Tianhe-2, and inferred from the current most efficient permanent-computing algorithms that an upper bound on the performance of Tianhe-2 is one 50-photon sample per ~100 min. In addition, we found a precision issue with one of two permanent-computing algorithms.