Neel-VBS phase boundary of the extended J_1-J_2 model with biquadratic interaction
Abstract
The J_1-J_2 model with the biquadratic (plaquette-four-spin) interaction was simulated with the numerical-diagonalization method. Some limiting cases of this model have been investigated thoroughly. Taking the advantage of the extended parameter space, we survey the phase boundary separating the N'eel and valence-bond-solid phases. According to the deconfined-criticality scenario, the singularity of this phase boundary is continuous, accompanied with unconventional critical indices. Diagonalizing the finite-size cluster with N \le 36 spins, we observe a signature of continuous phase transition. Our tentative estimate for the correlation-length critical exponent is \nu=1.1(3). In order to elucidate a non-local character of criticality, we evaluated the Roomany-Wyld \beta function around the critical point.
Keywords
Cite
@article{arxiv.1201.0804,
title = {Neel-VBS phase boundary of the extended J_1-J_2 model with biquadratic interaction},
author = {Yoshihiro Nishiyama},
journal= {arXiv preprint arXiv:1201.0804},
year = {2015}
}