We study the criticality of a long-range quantum ferromagnetic Ising chain with algebraically decaying interactions $1/r^{\alpha }$ via the fidelity susceptibility based on the exact diagonalization and the density-matrix renormalization-group techniques. We find that critical exponents change monotonically from the mean-field universality class to the short-range Ising universality class for intermediate $\alpha$, which are consistent with recent results obtained from renormalization-group techniques. In addition, we determine the critical values for $1.8\le \alpha \le 3$ from the finite-size scaling of the fidelity susceptibility. Our work provides very nice numerical data from the fidelity susceptibility for the quantum long-range ferromagnetic Ising chain.

• Received 14 May 2018

DOI:https://doi.org/10.1103/PhysRevA.98.023607