We studied the ground state phase diagram of spin-1/2 J1-J2 XY model on the square lattice with first- J1 and second-neighbor J2 antiferromagnetic interactions using both iDMRG and DMRG approaches. We show that a plaquette valence bond phase is realized in an intermediate region 0.50 <= J2/J1 <= 0.54 between a N\'eel magnetic ordered phase at J2/J1 < 0.50 and a stripy magnetic ordered phase at J2/J1 >= 0.54. The plaquette valence bond phase is characterized by finite dimer orders in both the horizontal and vertical directions. Contrary to the spin-1/2 J1-J2 Heisenberg model, we do not find numerical evidence for a quantum spin liquid phase in the J1-J2 XY model.
@article{arxiv.2212.04863,
title = {Plaquette valence bond state in spin-1/2 J1-J2 XY model on square lattice},
author = {Y. -H. Chan and Hong-Chen Jiang and Y. -C. Chen},
journal= {arXiv preprint arXiv:2212.04863},
year = {2023}
}