A comparative study of local quantum Fisher information and local quantum uncertainty in Heisenberg XY model

Abstract

Recently, it has been shown that the quantum Fisher information via local observables and via local measurements (i.e., local quantum Fisher information (LQFI)) is a central concept in quantum estimation and quantum metrology and captures the quantumness of correlations in multi-component quantum system [S. Kim et al., Phys. Rev. A. 97, 032326 (2018)]. This new discord-like measure is very similar to the quantum correlations measure called local quantum uncertainty (LQU). In the present study, we have revealed that LQU is bounded by LQFI in the phase estimation protocol. Also, a comparative study between these two quantum correlations quantifiers is addressed for the quantum Heisenberg XY model. Two distinct situations are considered. The first one concerns the anisotropic XY model and the second situation concerns isotropic XY model submitted to an external magnetic field. Our results confirm that LQFI reveals more quantum correlations than LQU.

Local quantum Fisher information and one-way quantum deficit in spin-1/2 XX Heisenberg chain with three-spin interaction

“…Generally, for an arbitrary quantum state ρ θ that depends on a variate θ, the QFI is expressed by [17],…”

Quantum Fisher Information and Bures Distance Correlations of Coupled Two Charge-Qubits Inside a Coherent Cavity with the Intrinsic Decoherence

“…QFI is employed to establish the link between quantum correlation and quantum metrology [30,31]. Recently, local quantum Fisher information (LQFI) is introduced as a quantifier of the nonclassical correlation beyond entanglement [32][33][34].…”

Local quantum uncertainty as a robust metric to characterize discord-like quantum correlations in subsets of the chromophores in photosynthetic light-harvesting complexes

“…Recently, it has been proved that LQU meets the criteria for a discord-like quantifier of quantum correlations. The LQU approach has been used as a reliable measure to characterize nonclassical correlations in a few frameworks [39][40][41][42][43][44] The general motivation for studying coherence and quantum correlations in light-harvesting structures is that the precise characterization of these quantum resources is essential, on the one hand, for understanding their functional relation with the energy transfer mechanism and, on ther other, to be able to construct naturally robust quantum devices based on that mechanics. Our principal aim is to demonstrate that the Local Quantum Uncertainty is a highly flexible, robust, and consistent metric to characterize quantum correlations, which is and a novel approach that had not been studied before.…”