Information flow and error scaling for fully quantum control

• Main Authors: Calarco, T. (Author), Caruso, F. (Author), Gherardini, S. (Author), Montangero, S. (Author), Müller, M.M (Author)
• Format: Article
• Language: English
• Published: American Physical Society 2022
• Subjects: Channel capacity; Control errors; Controllers; Errors; Information flows; Numerical data; Optimal controls; Quantum capacity; Quantum channel capacities; Quantum optics; Quantum system; Quantum technologies; Scaling behaviours; Scalings
• Online Access: View Fulltext in Publisher

 The optimally designed control of quantum systems is playing an increasingly important role to engineer novel and more efficient quantum technologies. Here, in the scenario represented by controlling an arbitrary quantum system via the interaction with an another optimally initialized auxiliary quantum system, we show that the quantum channel capacity sets the scaling behavior of the optimal control error. Specifically, by fitting the model to numerical data, we verify that the minimum control error is ensured by maximizing the quantum capacity of the channel mapping the initial control state into the target state of the controlled system, i.e., optimizing the quantum information flow from the controller to the system to be controlled. Analytical results, supported by numerical evidences, are provided when the systems and the controller are either qubits or single Bosonic modes. © 2022 authors. Published by the American Physical Society.