Abstract
The critical properties of the one-dimensional spin- transverse Ising model in the presence of a longitudinal magnetic field were studied by the quantum fidelity method. We used exact diagonalization to obtain the ground-state energies and corresponding eigenvectors for lattice sizes up to 24 spins. The maximum of the fidelity susceptibility was used to locate the various phase boundaries present in the system. The type of dominant spin ordering for each phase was identified by examining the corresponding ground-state eigenvector. For a given antiferromagnetic nearest-neighbor interaction , we calculated the fidelity susceptibility as a function of the transverse field and the longitudinal field . The phase diagram in the ()-plane shows three phases. These findings are in contrast with the published literature that claims that the system has only two phases. For , we observed an antiferromagnetic phase for small values of and a paramagnetic phase for large values of . For and low , we found a disordered phase that undergoes a second-order phase transition to a paramagnetic phase for large values of .
2 More- Received 22 August 2018
- Revised 23 November 2018
DOI:https://doi.org/10.1103/PhysRevE.99.012122
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