We calculate exactly the density of magnon states of the regularly alternating spin-1/2 XX chain with Dzyaloshinskii-Moriya interaction. The obtained results permit us to examine the stability of the chain with respect to spin-Peierls dimerization. We found that depending on the dependences of Dzyaloshinskii-Moriya interaction on distortion amplitude it may act either in favour of the dimerization or against the dimerization.
@article{arxiv.cond-mat/0001014,
title = {Spin-Peierls instability in the spin-1/2 transverse XX chain with Dzyaloshinskii-Moriya interaction},
author = {O. Derzhko and J. Richter and O. Zaburannyi},
journal= {arXiv preprint arXiv:cond-mat/0001014},
year = {2007}
}