Remote Quantum State Transfer for Qubites with Different Frequencies

A quantum communication system includes a first quantum transceiver, a second quantum transceiver, and a quantum communication mediator (QCM) system.  The transceivers have different resonant frequencies or physical systems.  The QCM system receives an initial quantum signal from the first quantum transceiver.  The QCM system transfers a quantum state of the initial quantum signal to a first mechanical signal and then from the first mechanical signal to a first pair of optical signals by way of a first three-wave mixing process.  The QCM transfers the quantum state to a second pair of optical signals from the first pair by way of a four-wave mixing process.  The QCM transfers the quantum state from the second pair of optical signals to a second mechanical signal by way of a second three-wave mixing process.  The QCM transfers the quantum state from the second mechanical signal to a final quantum signal by mechanical transduction.