Quantum Fisher Information Dynamics in the Presence of Intrinsic Decoherence

Abstract

We investigate the dynamics of quantum Fisher information (QFI) in two qubits when coupled to an external magnetic field. Isotropy, Dzyaloshinskii-Moriya interaction strength, magnetic field strength, and decoherence are system parameters used to characterize the QFI function. We show that when different parameters are used to characterize QFI, the dynamical layout changes significantly in both quantitative and qualitative terms. The estimation of various parameters is found to be greatly influenced by the relative parameter values as well as the type of QFI function used. The QFI functions showed a sudden rise and mostly a gradual decrease under Milburn decoherence, eventually reaching zero or non-zero final saturation levels. Furthermore, we discovered that the probability of all parameters being estimated remained high only for the initial values of the interaction time intervals instead of the later time intervals.