An error-correction scheme that encodes an unknown two-photon state into four photons, up to one of which can be lost in the transmission is presented. Such a device acts as a simple repeater or quantum transponder when it is placed in series, and it acts as an optical quantum memory when it is inserted in an optical loop. Using this scheme, the conversion between flying qubits and stationary qubits in memory is not necessary, as the memory and quantum logic gates are composed fo the same optical resources.
Publication Source (Journal or Book title)
Physical Review Letters
Gingrich, R., Kok, P., Lee, H., Vatan, F., & Dowling, J. (2003). All linear optical quantum memory based on quantum error correction. Physical Review Letters, 91 (21), 217901/1-217901/4. https://doi.org/10.1103/PhysRevLett.91.217901