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arXiv · 2503.23593

Measurement-induced back-action in a QD-based coherent spin-photon interface

Adrià Medeiros·Manuel Gundín·Dario A. Fioretto·Vincent Vinel·Eliott Rambeau·Elham Mehdi·Niccolo Somaschi·Aristide Lemaître·Isabelle Sagnes·Nadia Belabas·Olivier Krebs·Pascale Senellart·Loïc Lanco
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Abstract

Polarization-encoded spin-photon interfaces constitute promising candidates for the development of stationary nodes used as photon receivers, for quantum communication and distributed quantum computing. Here we introduce a time-resolved tomography approach which allows observing the dynamics of an electron spin, in a semiconductor quantum dot, mapped onto the dynamics of the polarization state of reflected photons. Through a single tomography experiment, we infer all the relevant spin dynamics timescales, including precession, decoherence and relaxation times. We also demonstrate and quantify the measurement back-action induced, on the embedded spin qubit, by the detection of a single reflected photon. We show that the induced population and coherence of the spin state can be tuned by the chosen polarization basis of the measurement. The control of the photon-induced back-action on the embedded spin qubit constitutes a crucial requirement for the use of spin-photon interfaces as quantum receivers.

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Adrià Medeiros, Manuel Gundín, Dario A. Fioretto, Vincent Vinel, Eliott Rambeau, Elham Mehdi, Niccolo Somaschi, Aristide Lemaître, Isabelle Sagnes, Nadia Belabas, Olivier Krebs, Pascale Senellart, Loïc Lanco. 2025-08-29. Measurement-induced back-action in a QD-based coherent spin-photon interface. https://arxiv.org/abs/2503.23593

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