Renormalization-group approach to quantum Fisher information in the two-dimensional XY model
School of Science, Jiangsu University of Science and Technology, 212003, Zhenjiang, China
Accepted: 7 November 2021
Published online: 18 November 2021
We have studied the relationship between the two-site quantum Fisher information and quantum phase transitions of a two-dimensional XY spin system based on the quantum renormalization-group method. By the five-site model, the quantum Fisher information and its first-derivatives are rigorously calculated, respectively. It is found that the first derivative of quantum Fisher information shows singular behavior, and the extreme point is quickly reached after few iterative steps as compared with one-dimensional spin chain. This singularity is exactly an indicator of the system’s second-order phase transition. The finite-size scaling behavior of the critical point is investigated and the scaling exponent is derived which describes the correlation length of this two-dimensional XY spin model.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021