Quantum feedback control typically involves three main steps: measurement, estimation, and feedback. First, a quantum measurement is performed on the system to gather information about its current state. Because quantum measurements can disturb the system, this step must be carefully designed. Next, the information obtained from the measurement is used to estimate the system's state, often employing complex algorithms and quantum state tomography. Finally, based on the estimated state, a feedback mechanism is applied to drive the system towards a desired state. This feedback can be implemented through various means, such as applying external fields or modifying the system's environment.
