Quantum Multi-Channel Decoupling

We study multiple-input multiple-output (MIMO) quantum systems and explore quantum decoupling techniques that can be used to facilitate the design of quantum networks. We provide a quantum state feedback control law to change the structure of a quantum system in order to decouple the multiple channels. We show that an MIMO quantum system can be decoupled as an aggregate of n separated single-input single-output (SISO) quantum systems from an input-output point of view. We also discuss the conditions under which quantum decoupling can be achieved. We illustrate our method with several qubit and atomic systems.