Journal Article

Quantum circuits with many photons on a programmable nanophotonic chip

Mahler, D. H., Dhand, I., Sabapathy, K. K., Janik, R., Kumar, S. P., Israel, R. B., Száva, A., Brádler, K., Su, D., Zabaneh, Z., Gerrits, T., Nam, S. W., Tan, K., Hundal, J., Zhang, Y., Lita, A. E., Jahangiri, S., Vernon, Z., Bergholm, V., Neuhaus, L., Quesada, N., Repingon, A., Arrazola, J. M., Bromley, T. R., Killoran, N., Tan, P., Helt, L. G., Lavoie, J., Vaidya, V. D., Menotti, M., Swinarton, J., Schuld, M., Morrison, B., Goussev, A., Fumagalli, A., Isacsson, T., Izaac, J., Qi, H. Y., Collins, M. J.

2021

Overview

Growing interest in quantum computing for practical applications has led to a surge in the availability of programmable machines for executing quantum algorithms 1 , 2 . Present-day photonic quantum computers 3 – 7 have been limited either to non-deterministic operation, low photon numbers and rates, or fixed random gate sequences. Here we introduce a full-stack hardware−software system for executing many-photon quantum circuit operations using integrated nanophotonics: a programmable chip, operating at room temperature and interfaced with a fully automated control system. The system enables remote users to execute quantum algorithms that require up to eight modes of strongly squeezed vacuum initialized as two-mode squeezed states in single temporal modes, a fully general and programmable four-mode interferometer, and photon number-resolving readout on all outputs. Detection of multi-photon events with photon numbers and rates exceeding any previous programmable quantum optical demonstration is made possible by strong squeezing and high sampling rates. We verify the non-classicality of the device output, and use the platform to carry out proof-of-principle demonstrations of three quantum algorithms: Gaussian boson sampling, molecular vibronic spectra and graph similarity 8 . These demonstrations validate the platform as a launchpad for scaling photonic technologies for quantum information processing. A system for realizing many-photon quantum circuits is presented, comprising a programmable nanophotonic chip operating at room temperature, interfaced with a fully automated control system.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/624/400/482 / 639/766/1130/2799 / 639/766/483/481 / Algorithms / Application programming interface / Automatic control / Automation / Circuits / Control systems / Data processing / Experiments / Humanities and Social Sciences / Information processing / Interferometers / Launching pads / Light / multidisciplinary / Photonics / Photons / Quantum computing / Quantum phenomena / Room temperature / Sampling / Science / Science (multidisciplinary) / Sequences / Silicon nitride / Software / Squeezed states (quantum theory)