Robustness and Optimization of Multi component Coherent Quantum Feedback Networks as Quantum Memory Systems

Quantum memories are physical devices that can store a quantum state or quantum mechanical operator for later retrieval. Quantum memories have important applications in quantum computing and quantum information processing. For example, a number of relevant quantum algorithms, including the Harrow-Hassidim-Lloyd algorithm for solving linear equations, the Lloyd-Mohseni-Rebentrost algo- rithm for principal component analysis, and the Kerenidis-Prakash algorithm for recommender systems, crucially rely on the efficient preparation and storage of quantum states in quantum memories. How- ever, quantum states are extremely sensitive to noise, decoherence, and errors.