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arXiv · 2608.05003

Universal linear manipulation via routing and projective measurements

Alessio Baldazzi·Sonia Mazzucchi·Lorenzo Pavesi
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Abstract

Multiport interferometers with $N$ ports are basic devices in both classical and quantum photonics. Ideally, they implement a linear unitary transformation between the input and output electric field vectors with $N$ components, each associated with a spatial mode of classical coherent light or a single photon. Standard designs for a fully reconfigurable universal multiport interferometer are given by the Reck or the Clements schemes. In this work, we introduce routing schemes to implement a generic unitary transformation on classical coherent light or single photons using linear or tree geometries via multiple projective measurements on a single detector with the minimum number of components. Then, we generalize this result to the case of any multi-photon state for scattershot boson sampling experiments with multi-routing schemes. Finally, we test the robustness of routing schemes compared to universal schemes with respect to losses and phase noise.

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Alessio Baldazzi, Sonia Mazzucchi, Lorenzo Pavesi. 2026-08-05. Universal linear manipulation via routing and projective measurements. https://arxiv.org/abs/2608.05003

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