Fidelity estimation of quantum states on a silicon photonic chip

Sabine Wollmann, Xiaogang Qiang*, Sam Pallister, Ashley Montanaro, Noah Linden, Jonathan C. F. Matthews

*Corresponding author for this work

Research output: Working paperPreprint

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As a measure of the 'closeness' of two quantum states, fidelity plays a fundamental role in quantum information theory. Fidelity estimation protocols try to strike a balance between information gleaned from an experiment, and the efficiency of its implementation, in terms of the number of states consumed by the protocol. Here we adapt a previously reported optimal state verification protocol (Phys. Rev. Lett. 120, 170502, 2018) for fidelity estimation of two-qubit states. We demonstrate the protocol experimentally using a fully-programmable silicon photonic two-qubit chip. Our protocol outputs significantly smaller error bars of its point estimate in comparison with another widely-used estimation protocol, showing a clear step forward in the ability to estimate the fidelity of quantum states produced by a practical device.
Original languageEnglish
Number of pages9
Publication statusPublished - 16 Jun 2023

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