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arXiv · 2305.06839

Direct observation of non-linear optical phase shift induced by a single quantum emitter in a waveguide

Mathias J. R. Staunstrup·Alexey Tiranov·Ying Wang·Sven Scholz·Andreas D. Wieck·Arne Ludwig·Leonardo Midolo·Nir Rotenberg·Peter Lodahl·Hanna Le Jeannic
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Abstract

Realizing a sensitive photon-number-dependent phase shift on a light beam is required both in classical and quantum photonics. It may lead to new applications for classical and quantum photonics machine learning or pave the way for realizing photon-photon gate operations. Non-linear phase-shifts require efficient light-matter interaction, and recently quantum dots coupled to nanophotonic devices have enabled near-deterministic single-photon coupling. We experimentally realize an optical phase shift of $0.19 \pi \pm 0.03$ radians ($\approx 34$ degrees) using a weak coherent state interacting with a single quantum dot in a planar nanophotonic waveguide. The phase shift is probed by interferometric measurements of the light scattered from the quantum dot in the waveguide. The nonlinear process is sensitive at the single-photon level and can be made compatible with scalable photonic integrated circuitry. The work may open new prospects for realizing high-efficiency optical switching or be applied for proof-of-concept quantum machine learning or quantum simulation demonstrations.

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Mathias J. R. Staunstrup, Alexey Tiranov, Ying Wang, Sven Scholz, Andreas D. Wieck, Arne Ludwig, Leonardo Midolo, Nir Rotenberg, Peter Lodahl, Hanna Le Jeannic. 2023-05-11. Direct observation of non-linear optical phase shift induced by a single quantum emitter in a waveguide. https://arxiv.org/abs/2305.06839

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