Usefulness of weak measurements in improving the precision of quantum parameter estimation
LIU Li-jun
Abstract：Quantum metrology concerns how to achieve the highest precision of physical parameters by quantum re-sources, which has broad applications in many fields. For closed quantum systems, the accuracy attained with entangled quantum probes can significantly surmount that of classical strategies. However, when noises such as decoherence are tak-en into account, the quantum gain may be jeopardized. In this paper, weak measurement is adopted to improve estimation precision in the presence of amplitude-damping decoherence, and it is demonstrated that the method of weak measurement can recover estimation precision to the Heisenberg limit, even though the success probability is in a exponential attenuation. Furthermore, the effectiveness of weak measurement in improving the estimation precision is investigated when ancillary systems are implemented.
Keywords：quantum parameter estimationweak measurementprecision limit
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 1471-1476 )