Scaling of excitations in dimerized and frustrated spin-1/2 chains
Abstract
We study the finite-size behavior of the low-lying excitations of spin-1/2 Heisenberg chains with dimerization and next-to-nearest neighbors interaction, J_2. The numerical analysis, performed using density-matrix renormalization group, confirms previous exact diagonalization results, and shows that, for different values of the dimerization parameter \delta, the elementary triplet and singlet excitations present a clear scaling behavior in a wide range of \ell=L/\xi (where L is the length of the chain and \xi is the correlation length). At J_2=J_2c, where no logarithmic corrections are present, we compare the numerical results with finite-size predictions for the sine-Gordon model obtained using Luscher's theory. For small \delta we find a very good agreement for \ell > 4 or 7 depending on the excitation considered.
Cite
@article{arxiv.cond-mat/0503539,
title = {Scaling of excitations in dimerized and frustrated spin-1/2 chains},
author = {D. Controzzi and C. Degli Esposti Boschi and F. Ortolani and S. Pasini},
journal= {arXiv preprint arXiv:cond-mat/0503539},
year = {2007}
}
Comments
4 pages, 4 eps figures, RevTeX 4 class, same version as in PRB