Real-time Information, Uncertainty and Quantum Feedback Control
arXiv:1409.2933
Abstract
Feedback is the core concept in cybernetics and its effective use has made great success in but not limited to the fields of engineering, biology, and computer science. When feedback is used to quantum systems, two major types of feedback control protocols including coherent feedback control (CFC) and measurement-based feedback control (MFC) have been developed. In this paper, we compare the two types of quantum feedback control protocols by focusing on the real-time information used in the feedback loop and the capability in dealing with parameter uncertainty. An equivalent relationship is established between quantum CFC and non-selective quantum MFC in the form of operator-sum representation. Using several examples of quantum feedback control, we show that quantum MFC can theoretically achieve better performance than quantum CFC in stabilizing a quantum state and dealing with Hamiltonian parameter uncertainty. The results enrich understanding of the relative advantages between quantum MFC and quantum CFC, and can provide useful information in choosing suitable feedback protocols for quantum systems.
arXiv comment24 pages
References in corpus (18)
- Quantum control theory and applications: A survey
- Real-time quantum feedback prepares and stabilizes photon number states
- Quantum feedback control of a superconducting qubit: Persistent Rabi oscillations
- Feedback control of quantum state reduction
- Coherent quantum LQG control
- Adaptive homodyne measurement of optical phase
- Continuous quantum error correction via quantum feedback control
- Coherent-feedback quantum control with a dynamic compensator
- All-optical versus electro-optical quantum-limited feedback
- Quantum State Tomography via Linear Regression Estimation
- Optimal Unravellings for Feedback Control in Linear Quantum Systems
- Adaptive quantum state tomography improves accuracy quadratically
- Advantages of Coherent Feedback for Cooling Quantum Oscillators
- Bayesian feedback versus Markovian feedback in a two-level atom
- Information, disturbance and Hamiltonian quantum feedback control
- Quantum Coherent Nonlinear Feedbacks with Applications to Quantum Optics on Chip
- Feedback Control of Non-linear Quantum Systems: a Rule of Thumb
- Adaptive Measurements in the Optical Quantum Information Laboratory