Towards quantum-enhanced sensing and imaging with multi-parameter estimation
Quantum metrology for single parameter estimation has achieved great success. Yet many practical applications involve multiple parameters. Therefore, extending quantum metrology to multi-parameter estimation will greatly enlarge its scope. However, not only the quantum-enhanced estimation of multiple parameters is technically more challenging compared to its single-parameter counterpart, but the fundamental limit of its precision remains elusive. In particular, due to the incompatibility in quantum mechanics, there are tradeoffs between the precisions of different parameters. In this talk I will present our recent works on multi-parameter quantum metrology. For the applications, we demonstrate how multi-parameter quantum metrology allows us to overcome Rayleigh’s criterion and enhance the resolution of imaging in three-dimensional space. In addition, we propose and demonstrate the use of antiunitary symmetry and classical correlations to eliminate the tradeoffs between different parameters and achieve the optimal precision simultaneously for all parameters.