https://doi.org/10.1140/epjqt/s40507-022-00142-1
Research
Arbitrary unitaries in orbital angular momentum of single photons
1
Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090, Vienna, Austria
2
Institute for Quantum Optics and Quantum Information – Vienna, Austrian Academy of Sciences, Boltzmanngasse 3, 1090, Vienna, Austria
a
jaroslav.kysela@univie.ac.at
Received:
21
March
2022
Accepted:
6
August
2022
Published online:
17
August
2022
A simple argument is presented that explicitly shows how to construct an arbitrary quantum gate acting on orbital angular momentum (OAM) of single photons. The scheme can be applied to implement subspace multiplexing, where a single high-dimensional OAM qudit represents effectively a stack of multiple independent lower-dimensional qudits. A special subclass of unitaries composed of single-photon controlled gates is studied in detail and notable examples of the general approach are discussed. The generalization of the simple argument leads to the parallelization scheme, which results in the savings of resources. The presented schemes utilize only conventional optical elements and apply not only to single photons but also to classical light.
Key words: Orbital angular momentum / Arbitrary unitary / Single-photon gates / Quantum computation
© The Author(s) 2022
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