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arXiv · 1703.06693

Polynomial approximation of non-Gaussian unitaries by counting one photon at a time

Francesco Arzani·Nicolas Treps·Giulia Ferrini
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Abstract

In quantum computation with continous-variable systems, quantum advantage can only be achieved if some non-Gaussian resource is available. Yet, non-Gaussian unitary evolutions and measurements suited for computation are challenging to realize in the lab. We propose and analyze two methods to apply a polynomial approximation of any unitary operator diagonal in the amplitude quadrature representation, including non-Gaussian operators, to an unknown input state. Our protocols use as a primary non-Gaussian resource a single-photon counter. We use the fidelity of the transformation with the target one on Fock and coherent states to assess the quality of the approximate gate.

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Francesco Arzani, Nicolas Treps, Giulia Ferrini. 2017-06-12. Polynomial approximation of non-Gaussian unitaries by counting one photon at a time. https://doi.org/10.1103/physreva.95.052352

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