Measurement-based quantum correlation in mixed-state quantum metrology

Abstract

Entanglement is crucial for realizing quantum advantages in metrology. However, entanglement has been outcast by discord in order to capture the worst-case sensitivity in quantum metrology to estimate an unknown parameter. In contrast to traditional measures—namely entanglement and discord—there exist noncommutativity-based quantum correlation measures induced by local von Neumann measurements. Such correlations are more comprehensive than entanglement and discord in quantum information processing. In this paper, we investigate the metrological resourcefulness of measurement-based quantum correlations (MbQCs). We provide a lower bound on the minimum precision of the estimation in terms of the MbQC. We show that the MbQC is more resourceful in quantum metrology than entanglement and super quantum discord. For any non-product state, the MbQC gives a metrological insight into the sensitivity of a mixed state toward perturbation caused by a local von Neumann measurement.