Breakdown of the perturbative renormalization group for S >= 1 random antiferromagnetic spin chains
Disordered Systems and Neural Networks
2009-10-31 v1
Abstract
We investigate the application of a perturbative renormalization group (RG) method to random antiferromagnetic Heisenberg chains with arbitrary spin size. At zero temperature we observe that initial arbitrary probability distributions develop a singularity at J=0, for all values of spin S. When the RG method is extended to finite temperatures, without any additional assumptions, we find anomalous results for S >= 1. These results lead us to conclude that the perturbative scheme is not adequate to study random chains with S >= 1. Therefore a random singlet phase in its more restrictive definition is only assured for spin-1/2 chains.
Keywords
Cite
@article{arxiv.cond-mat/0011479,
title = {Breakdown of the perturbative renormalization group for S >= 1 random antiferromagnetic spin chains},
author = {A. Saguia and B. Boechat and M. A. Continentino and O. F. de Alcantara Bonfim},
journal= {arXiv preprint arXiv:cond-mat/0011479},
year = {2009}
}
Comments
5 pages, 3 figures. To appear in Physical Review B