Quantum memory is an essential device for quantum communications systems and quantum computers. An important category of quantum memory, called Optically controlled quantum memory, uses a strong classical beam to control the storage and re-emission of a single photon signal through an atomic ensemble. The residual light from the strong classical control beam can cause severe noise and degrade the system performance significantly. Efficiently suppressing this noise is required for the successful implementation of optically controlled quantum memories. In this paper, we briefly introduce the latest and most common approaches to quantum memory and review the various noise reduction techniques used in implementing them.
Modern Physics Letters B
Noise Reduction, Quantum Memory, Quantum Communication