  Implementing large instances of quantum algorithms requires the processing of
many quantum information carriers in a hardware platform that supports the
integration of different components. While established semiconductor
fabrication processes can integrate many photonic components, the generation
and algorithmic processing of many photons has been a bottleneck in integrated
photonics. Here we report the on-chip generation and processing of quantum
states of light with up to eight photons in quantum sampling algorithms.
Switching between different optical pumping regimes, we implement the
Scattershot, Gaussian and standard boson sampling protocols in the same silicon
chip, which integrates linear and nonlinear photonic circuitry. We use these
results to benchmark a quantum algorithm for calculating molecular vibronic
spectra. Our techniques can be readily scaled for the on-chip implementation of
specialised quantum algorithms with tens of photons, pointing the way to
efficiency advantages over conventional computers.
