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arXiv · 2410.15697

Programmable entangled qubit states on a linear-optical platform

N. N. Skryabin·Yu. A. Biriukov·M. A. Dryazgov·S. A. Fldzhyan·S. A. Zhuravitskii·A. S. Argenchiev·I. V. Kondratyev·L. A. Tsoma·K. I. Okhlopkov·I. M. Gruzinov·K. V. Taratorin·M. Yu. Saygin·I. V. Dyakonov·M. V. Rakhlin·A. I. Galimov·G. V. Klimko·S. V. Sorokin·I. V. Sedova·M. M. Kulagina·Yu. M. Zadiranov·A. A. Toropov·S. A. Evlashin·A. A. Korneev·S. P. Kulik·S. S. Straupe
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Abstract

We present an experimental platform for linear-optical quantum information processing. Our setup utilizes multiphoton generation using a high-quality single-photon source, which is demultiplexed across multiple spatial channels, a custom-designed, programmable, low-loss photonic chip, and paired with high-efficiency single-photon detectors. We demonstrate the platform's capability in producing heralded arbitrary two-qubit dual-rail encoded states, a crucial building block for large-scale photonic quantum computers. The programmable chip was fully characterized through a calibration process that allowed us to create a numerical model accounting for fabrication imperfections and measurement errors. As a result, using on-chip quantum state tomography (QST), we achieved high-fidelity quantum state preparation, with a fidelity of 98.5\% specifically for the Bell state.

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N. N. Skryabin, Yu. A. Biriukov, M. A. Dryazgov, S. A. Fldzhyan, S. A. Zhuravitskii, A. S. Argenchiev, I. V. Kondratyev, L. A. Tsoma, K. I. Okhlopkov, I. M. Gruzinov, K. V. Taratorin, M. Yu. Saygin, I. V. Dyakonov, M. V. Rakhlin, A. I. Galimov, G. V. Klimko, S. V. Sorokin, I. V. Sedova, M. M. Kulagina, Yu. M. Zadiranov, A. A. Toropov, S. A. Evlashin, A. A. Korneev, S. P. Kulik, S. S. Straupe. 2024-10-21. Programmable entangled qubit states on a linear-optical platform. https://arxiv.org/abs/2410.15697

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