Two-dimensional easy-plane SU(3) magnet with the transverse field: anisotropy-driven multicriticality

The two-dimensional easy-plane SU(3) magnet subjected to the transverse field was investigated with the exact-diagonalization method. So far, as to the XY model (namely, the easy-plane SU(2) magnet), the transverse-field-driven order-disorder phase boundary has been investigated with the exact-diagonalization method, and it was claimed that the end-point singularity (multicriticality) at the XX-symmetric point does not accord with large-N-theory's prediction. Aiming to reconcile the discrepancy, we extend the internal symmetry to the easy-plane SU(3) with the anisotropy parameter eta, which interpolates the isotropic (eta = 0) and fully anisotropic (eta = 1) cases smoothly. As a preliminary survey, setting eta = 1, we analyze the order-disorder phase transition through resorting to the fidelity susceptibility chi(F), which exhibits a pronounced signature for the criticality. Thereby, with eta scaled carefully, the chi(F) data are cast into the crossover-scaling formula so as to determine the crossover exponent phi, which seems to reflect the extension of the internal symmetry group to SU(3).

Automated summary

The study investigated the two-dimensional easy-plane SU(3) magnet under the influence of a transverse field using the exact-diagonalization method, aiming to reconcile discrepancies in large-N theory predictions. By extending the internal symmetry to easy-plane SU(3) with an anisotropy parameter eta, the study found that the introduction of eta could explain the singularity phenomenon observed in transverse-field-driven order-disorder phase transitions within certain limits.