Modified spin-wave study of random antiferromagnetic-ferromagnetic spin chains
Disordered Systems and Neural Networks
2009-11-07 v1
Abstract
We study the thermodynamics of one-dimensional quantum spin-1/2 Heisenberg ferromagnetic system with random antiferromagnetic impurity bonds. In the dilute impurity limit, we generalize the modified spin-wave theory for random spin chains, where local chemical potentials for spin-waves in ferromagnetic spin segments are introduced to ensure zero magnetization at finite temperature. This approach successfully describes the crossover from behavior of pure one-dimensional ferromagnet at high temperatures to a distinct Curie behavior due to randomness at low temperatures. We discuss the effects of impurity bond strength and concentration on the crossover and low temperature behavior.
Cite
@article{arxiv.cond-mat/0203326,
title = {Modified spin-wave study of random antiferromagnetic-ferromagnetic spin chains},
author = {Xin Wan and Kun Yang and R. N. Bhatt},
journal= {arXiv preprint arXiv:cond-mat/0203326},
year = {2009}
}
Comments
14 pages, 7 eps figures