Sample-Efficient Adaptive Calibration of Quantum Networks Using Bayesian Optimization
All physical systems employed for quantum information tasks must act as unbiased carriers of encoded quantum states. Ensuring such indistinguishability of information carriers is a major challenge in many quantum information applications, including advanced quantum communication protocols. For photons, the workhorses of quantum communication networks, it is difficult to obtain and maintain their indistinguishability because of environment-induced transformations and loss imparted by communication channels, especially in noisy scenarios. Conventional strategies to mitigate these transformations often require hardware or software overhead that is restrictive (e.g., adding noise), infeasible (e.g., on a satellite), or time-consuming for deployed networks. Here we propose and develop resource-efficient Bayesian optimization techniques to rapidly and adaptively calibrate the indistinguishability of individual photons for quantum networks using only information derived from their measurement. To experimentally validate our approach, we demonstrate the optimization of Hong-Ou-Mandel interference between two photons–a central task in quantum networking– finding rapid, efficient, and reliable convergence towards maximal photon indistinguishability in the presence of high loss and shot noise. We expect our resource-optimized and experimentally friendly methodology will allow fast and reliable calibration of indistinguishable quanta, a necessary task in distributed quantum computing, communications, and sensing, as well as for fundamental investigations.
© 2022 American Physical Society. (Received 24 June 2021; revised 3 November 2021; accepted 25 February 2022; published 28 March 2022) We thank E. M. Constantintescu for discussions on Gaussian process modeling and R. Valivarthi for discussions in the early stages of this work. We thank J.-R. Vlimant for reading and commenting on the manuscript. The detectors were provided by V. B. Verma, F. Marsili, M. Shaw, and S. W. Nam. The SPDC waveguides were provided by L. Oesterling through a collaboration with W. Tittel. This work was performed, in part, at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, and supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. This work is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences operating under Contract Number DE-AC02-06CH11357. N.L. and N.S. acknowledge support from the AQT Intelligent Quantum Networks and Technologies (INQNET) research program. N.S. further acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC). P.L. and D.O. acknowledge support from the Natural Sciences and Engineering Research Council of Canada through the Discovery Grants Program and the CREATE QUANTA training program, and the Alberta Ministry for Jobs, Economy and Innovation through the Major Innovation Fund Quantum Technologies Project (QMP).
Submitted - 2106.06113.pdf
Published - PhysRevApplied.17.034067.pdf