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arXiv · 2507.16578

Ultrastable, low-error dynamic polarization encoding of deterministically generated single photons

Joscha Hanel·Zenghui Jiang·Jipeng Wang·Frederik Benthin·Tom Fandrich·Eddy Patrick Rugeramigabo·Raphael Joos·Michael Jetter·Simone Luca Portalupi·Jingzhong Yang·Michael Zopf·Peter Michler·Fei Ding
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Abstract

The ability to inscribe information on single photons at high speeds is a crucial requirement for quantum applications such as quantum communication and measurement-based photonic quantum computation. Nowadays, most experimental implementations employ phase modulators in single-pass, Mach-Zehnder interferometer or Michelson interferometer configurations to encode information on photonic qubits. However, these approaches are intrinsically sensitive to environmental influences, limiting the achievable quantum error rates in practice. We report on the first demonstration of a polarization encoder for single-photon qubits based on a free-space Sagnac interferometer, showcasing inherent phase stability and overcoming previous error rate limitations. Telecom-wavelength single photons emitted by a quantum dot are modulated by the encoder under a repetition rate of 152 MHz. A quantum bit error rate of 0.69(2)% is achieved, marking the lowest error rate reported to date for high-speed information encoding on single photons. This work represents a key advance towards robust, scalable, and low-error quantum information processing with single photon sources.

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Joscha Hanel, Zenghui Jiang, Jipeng Wang, Frederik Benthin, Tom Fandrich, Eddy Patrick Rugeramigabo, Raphael Joos, Michael Jetter, Simone Luca Portalupi, Jingzhong Yang, Michael Zopf, Peter Michler, Fei Ding. 2025-07-22. Ultrastable, low-error dynamic polarization encoding of deterministically generated single photons. https://doi.org/10.1103/lm15-czbv

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