Fidelity susceptibility study of quantum long-range antiferromagnetic Ising chain

We study the fidelity susceptibility of a quantum antiferromagnetic Ising chain with a long-range power-law interaction 1 /r^α using the large-scale density matrix renormalization group method. We find that the critical adiabatic dimension μ =2 and the critical exponent of the correlation length ν =1 for arbitrary α >0 , indicating all quantum phase transitions are second-order Ising transitions. In addition, we numerically determine the complete phase diagram for 0 <α ≤3 from the data collapse of the fidelity susceptibility and show that the critical point h_c changes monotonously with respect to α . This work will shed light on the nature of phase transitions in the quantum long-range antiferromagnetic Ising chain from a quantum information perspective.