Efficient Conversion of Multi-Qubit States for Distant Quantum Memories Via Time-Bin Multiplexing

Specific methods are proposed for converting an n-atom Greenberger-Horne-Zeilinger (GHZ) state into a W states and for converting an n-atom Knill-Laflamme-Milburn (KLM) state to a GHZ states by using only one single photon with high-dimension which works as a common-data bus connecting all stationary qubits. These parallel protocols can significantly increase the efficiency of quantum state conversion by reducing the exponential transmission loss via time-bin multiplexing. Finally, the feasibility of these schemes are assessed with currently achieved experimental parameters, showing that these schemes are feasible with currently experimental technology. The protocols linking these three entangled states may be useful for quantum information processing tasks based on them.