We study the fidelity susceptibility in the two-dimensional(2D) transverse
field Ising model and the 2D XXZ model numerically. It is found that in both
models, the fidelity susceptibility as a function of the driving parameter
diverges at the critical points. The validity of the fidelity susceptibility to
signal for the quantum phase transition is thus verified in these two models.
We also compare the scaling behavior of the extremum of the fidelity
susceptibility to that of the second derivative of the ground state energy.
From those results, the theoretical argument that fidelity susceptibility is a
more sensitive seeker for a second order quantum phase transition is also
testified in the two models.Comment: 6 pages, 7 figure
