Plaquette Order in the J1-J2-J3 model: a series expansion analysis
Abstract
Series expansion based on the flow equation method is employed to study the zero temperature properties of the spin-1/2 J1-J2-J3 antiferromagnet in two dimensions. Starting from the exact limit of decoupled plaquettes in a particular generalized J1-J2-J3 model we analyze the evolution of the ground state energy and the elementary triplet excitations in powers of all three inter-plaquette couplings up to fifth order. We find the plaquette phase to remain stable over a wide range of exchange couplings and to connect adiabatically up to the case of the plain J1-J2-J3 model, however not to the J1-J2 model at J3=0. Besides confirming the existence of such a phase, recently predicted by Mambrini, et al. [Phys. Rev. B 74, 144422 [2006)], we estimate its extent by Dlog-Pade analysis of the critical lines that result from closure of the triplet gap.
Keywords
Cite
@article{arxiv.0808.2229,
title = {Plaquette Order in the J1-J2-J3 model: a series expansion analysis},
author = {Marcelo Arlego and Wolfram Brenig},
journal= {arXiv preprint arXiv:0808.2229},
year = {2009}
}
Comments
6 pages, 5 figures