We study the effect of spin anisotropies on a frustrated quantum antiferromagnet using the J_1-J_2^{XXZ} model on the square lattice. The T=0 and finite-T phase diagrams of this model are obtained utilizing spin-wave theory, exact diagonalization, and quantum Monte Carlo. We find that anisotropic frustration tends to stabilize XY- and Ising-like ordered phases, while the disordered spin-liquid phase is restricted to a small region of the phase diagram. The ordered phases are separated by first-order transitions and exhibit a non-trivial reentrance phenomenon.
@article{arxiv.cond-mat/0403375,
title = {Anisotropy-induced ordering in the quantum J1-J2 antiferromagnet},
author = {Tommaso Roscilde and Adrian Feiguin and Alexander L. Chernyshev and Shiu Liu and Stephan Haas},
journal= {arXiv preprint arXiv:cond-mat/0403375},
year = {2009}
}