As quantum systems for information processing and communication continue to grow in size and complexity, novel methods of transferring and storing quantum information are needed. Quantum memory elements must retain quantum information much longer than their processing counterparts, transfer information quickly and efficiently to and from processing and flying qubits, be capable of heralding entanglement and teleportation events across a quantum network, and be scalable to large numbers of qubits. Hybrid mechanical systems, which use mechanical oscillators to control and connect quantum elements, are poised to fulfill just such a role and have grown in prominence in recent years due to their ability to couple to a wide variety of quantum systems and the number of practical advantages mechanical systems have over their photonic analogues. Furthermore, optomechanical crystal (OMC) devices, which leverage interactions between light and mechanical motion, have demonstrated many of the requirements for quantum memories. We seek to build upon previous efforts at implementing an OMC quantum memory by using diamond as a host material and coupling our diamond OMCs to a highly-coherent silicon-vacancy center spin as a long-lived quantum memory element. By adding this additional memory component and using diamond as our host material, we aim to develop a quantum memory and quantum communication platform that is resistant to optical absorption heating that has plagued silicon implementations and which can be scaled up and integrated into large-scale quantum networks. Potential NASA Applications (Limit 1500 characters, approximately 150 words): The proposed diamond quantum memory will serve as a a scalable building block for quantum network nodes, providing an integrated quantum memory and quantum entanglement distribution system for NASA's goal of developing a quantum network for distributed quantum computing and sensing applications. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): The proposed system fulfills an anticipated need in the commercial quantum computing sector for quantum networking elements between diverse implementations of quantum computers. By enabling links between quantum processing nodes, our system will expand the possibilities for and power of distributed quantum computation for commercial applications in quantum cryptography and quantum simulation. Duration: 13
