Renormalization of concurrence and quantum Fisher information in two-dimensional XXZ model

Abstract

We investigate two-dimensional anisotropic spin- $$\frac{1}{2}$$ lattice for XXZ model using concurrence and quantum Fisher information. The model is solved by using quantum renormalization group method and observed the quantum phase transition in thermodynamic limit. After sufficient iterations of quantum renormalization group, the concurrence and quantum Fisher information both attain two different saturated values that represent two different phases, the Neel phase and the spin fluid phase. The first-order derivative and the scaling behavior of both the concurrence and the quantum Fisher information are studied. At phase transition point, the non-analytic behavior of the derivative as a function of lattice size is discussed. Moreover, we observe that the scaling exponent for the concurrence and the quantum Fisher information describe the correlation length of the model at the critical point.