Quantum Phase Transitions in a Two-leg XXZ Ladder:Ground-state Fidelity

J. C. Xavier, E. Miranda

Po Chen, Chenrong Liu

R. Citro, E. Orignac

Jie Ren, Shiqun Zhu

The fidelity susceptibility and entanglement entropy in a system of two-leg XXZ spin ladder with rung coupling is investigated by using exact diagonalization of the system. The effects of rung coupling on fidelity susceptibility, entanglement entropy, and quantum phase transition are analyzed. It is found that the quantum phase transition between two different XY phases can be well-characterized by the fidelity susceptibility. Although the quantum phase transition from XY phase to rung singlet phase can be hardly detected by fidelity susceptibility, it can be predicted by the first derivative of the entanglement entropy of the system.

Sheng-Hao Li, Qian‐Qian Shi, Yaoheng Su +3 more

We have developed an efficient tensor network algorithm for spin ladders, which generates ground-state wave functions for infinite-size quantum spin ladders. The algorithm is able to efficiently compute the ground-state fidelity per lattice site, a universal phase transition marker, thus offering a powerful tool to unveil quantum many-body physics underlying spin ladders. To illustrate our scheme, we consider the two-leg and three-leg Heisenberg spin ladders with staggering dimerization, the two-leg Heisenberg spin ladder with cyclic four-spin exchange, and the ferromagnetic frustrated two-leg ladder. The ground-state phase diagrams thus yielded are reliable, compared with the previous studies based on the the exact diagonalization and the density matrix renormalization group. Our results indicate that the ground-state fidelity per lattice site successfully captures quantum criticalities in spin ladders.

敬吾 肘井