Optimal Measurement on Noisy Quantum Systems
Yu Watanabe, Takahiro Sagawa, Masahito Ueda · Physical Review Letters · 2010
We identify the optimal measurement for obtaining information about the original quantum state after the state to be measured has undergone partial decoherence due to noise. We quantify the information that can be obtained by the measurement in terms of the Fisher information and find its value for the optimal measurement. We apply our results to a quantum control scheme based on a spin-boson model.