2012/09/17 by Chiara Vitelli, Nicolò Spagnolo, Lorenzo Aparo +3
Computer Science · Physics and Astronomy · #One-way quantum computer #Open quantum system #Photon #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum entanglement #Quantum error correction #Quantum information #Quantum information science #Quantum mechanics #Quantum network #Quantum optics and atomic interactions #Quantum sensor #Quantum state #Quantum technology #Quantum teleportation #Qubit #physics.optics #quant-ph
paper · pdf · doi:10.1038/nphoton.2013.107
published as Nature Photonics 7, 521-526 (2013) · 7 pages main paper plus 9 pages supplementary materials
arxiv created 2012/09/17 · openalex publication_date 2013/05/03 · arxiv updated 2013/08/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Photons are the ideal carriers of quantum information for communication. Each photon can have a single qubit or even multiple qubits encoded in its internal quantum state, as defined by optical degrees of freedom such as polarization, wavelength, transverse modes, etc. Here, we propose and experimentally demonstrate a physical process, named "quantum state fusion", in which the two-dimensional quantum states (qubits) of two input photons are combined into a single output photon, within a four-dimensional quantum space. The inverse process is also proposed, in which the four-dimensional quantum state of a single photon is split into two photons, each carrying a qubit. Both processes can be iterated, and hence may be used to bridge multi-particle protocols of quantum information with the multi-degree-of-freedom ones, with possible applications in quantum communication networks.