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arXiv · 2604.06584

Deterministic linear-optical computing with symmetry-based qubits

David S. Simon·Christopher R. Schwarze·Anthony D. Manni·Abdoulaye Ndao·Alexander V. Sergienko
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Abstract

A particular type of linear optical multiport, the Grover four-port, has previously been shown to couple the spatial symmetry of a photon to its direction of travel. It is shown here that use of a nonstandard choice of qubit, based on symmetry, allows Grover four ports to act as compact, low-resource deterministic linear optical controlledNOTgates, with no post-selection or ancilla measurements required. This approach allows programmable devices, made from Grover multiports in combination with other standard optical components, that can implement multiple different one-, two-, and three-qubit gates, including the Fredkin and Toffoli gates.

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David S. Simon, Christopher R. Schwarze, Anthony D. Manni, Abdoulaye Ndao, Alexander V. Sergienko. 2026-04-08. Deterministic linear-optical computing with symmetry-based qubits. https://doi.org/10.1007/s11128-026-05157-6

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