Quantification of correlations by Fisher matrix

Quantum Fisher Information (QFI) is a relative-entropy-based measure of the distinctiveness of statistical ensembles. When applied to a lattice model, it quantifies the measurable difference between two instances of the model characterized by different parameter values. In my work, I demonstrate the significance of QFI in understanding microscopic properties of correlated quantum particles. The results are verified numerically. I compare the QFI across several important lattice models including the bosonic and fermionic Hubbard models as well as the Heisenberg model. Furthermore, I discuss how QFI relates to physically measurable quantities.