Haidong Yuan-Optimal Quantum Control for Quantum Metrology

Speaker:Haidong Yuan

Title:Optimal Quantum Control for Quantum Metrology


Measurement and estimation of parameters are essential for science and engineering, where the main quest is to find out the highest achievable precision with given resources and design schemes to attain it. With recent development of technology, it is now possible to design measurement protocols utilizing quantum mechanical effects, such as entanglement, to attain far better precision than classical schemes. This has found wide applications in quantum phase estimation, quantum imaging, atomic clock synchronization, etc, and created a high demand for better understanding of measurement protocols based on quantum mechanical effects. In this talk I will present a general framework for quantum metrology which relates the ultimate precision limit to the underlying quantum dynamics. This framework provides efficient methods for computing the ultimate precision limit and optimal schemes to attain it. I will show that with noiseless dynamics a universal time scaling emerges as a fundamental property under the optimal controlled schemes for quantum metrology, and the optimally controlled scheme outperforms the entanglement scheme for multi-parameter quantum metrology. If time permits, I will also talk about how the cooperation between quantum control and noises can further improve the precision limit.