We have employed spin-polarized scanning tunneling microscopy and Monte-Carlo simulations to investigate the effect of lateral confinement onto the nanoskyrmion lattice in Fe/Ir(111). We find a strong coupling of one diagonal of the square magnetic unit cell to the close-packed edges of Fe nanostructures. In triangular islands this coupling in combination with the mismatching symmetries of the islands and of the square nanoskyrmion lattice leads to frustration and triple-domain states. In direct vicinity to ferromagnetic NiFe islands, the surrounding skyrmion lattice forms additional domains. In this case a side of the square magnetic unit cell prefers a parallel orientation to the ferromagnetic edge. These experimental findings can be reproduced and explained by Monte-Carlo simulations. Here, the single-domain state of a triangular island is lower in energy, but nevertheless multi-domain states occur due to the combined effect of entropy and an intrinsic domain wall pinning arising from the skyrmionic character of the spin texture.
@article{arxiv.1606.08163,
title = {Skyrmions at the edge: Confinement effects in Fe/Ir(111)},
author = {J. Hagemeister and D. Iaia and E. Y. Vedmedenko and K. von Bergmann and A. Kubetzka and R. Wiesendanger},
journal= {arXiv preprint arXiv:1606.08163},
year = {2016}
}
Comments
5 pages, 4 figures, supplement not uploaded to arXiv due to size limitation