Quantum memory surpasses classical limits for storing unknown quantum operations

Quantum memories, systems that store and retrieve information leveraging quantum mechanical effects, can outperform classical storage systems on some existing tasks. Yet these promising memories could also complete operations that are very difficult or impossible for classical systems, including the storage and retrieval of so-called isometry channels. Quantum memories, systems that store and retrieve information leveraging quantum mechanical effects, can outperform classical storage systems on some existing tasks. Yet these promising memories could also complete operations that are very difficult ... [6450 chars]