In epitaxial MnSi/Si(111) films, the in-plane magnetization saturation is never reached due to the formation of specific surface chiral modulations with the propagation direction perpendicular to the film surfaces [Wilson et al. Phys. Rev. B 88, 214420 (2013)]. In this paper we show that the occurrence of such chiral surface twists is a general effect attributed to all bulk and con- fined magnetic crystals lacking inversion symmetry. We present experimental investigations of this phenomenon in nanolayers of MnSi/Si(111) supported by detailed theoretical analysis within the standard phenomenological model. In magnetic nanolayers with intrinsic or induced chirality, such surface induced instabilities become sizeable effects and play a crucial role in the formation of skyrmion lattices and other nontrivial chiral modulations.
@article{arxiv.1405.5275,
title = {Surface twist instabilities and skyrmion states in chiral ferromagnets},
author = {S. A. Meynell and M. N. Wilson and H. Fritzsche and A. N. Bogdanov and T. L. Monchesky},
journal= {arXiv preprint arXiv:1405.5275},
year = {2015}
}