Disorder Induced Phases in Higher Spin Antiferromagnetic Heisenberg Chains
Statistical Mechanics
2009-11-10 v2 Disordered Systems and Neural Networks
Abstract
Extensive DMRG calculations for spin S=1/2 and S=3/2 disordered antiferromagnetic Heisenberg chains show a rather distinct behavior in the two cases. While at sufficiently strong disorder both systems are in a random singlet phase, we show that weak disorder is an irrelevant perturbation for the S=3/2 chain, contrary to what expected from a naive application of the Harris criterion. The observed irrelevance is attributed to the presence of a new correlation length due to enhanced end-to-end correlations. This phenomenon is expected to occur for all half-integer S > 1/2 chains. A possible phase diagram of the chain for generic S is also discussed.
Keywords
Cite
@article{arxiv.cond-mat/0301067,
title = {Disorder Induced Phases in Higher Spin Antiferromagnetic Heisenberg Chains},
author = {Enrico Carlon and Péter Lajkó and Heiko Rieger and Ferenc Iglói},
journal= {arXiv preprint arXiv:cond-mat/0301067},
year = {2009}
}
Comments
6 Pages and 6 figures. Final version as published