It is demonstrated by means of density functional and ab-initio quantum chemical calculations, that transition metal - carbon systems have the potential to enhance the presently achievable area density of magnetic recording by three orders of magnitude. As a model system, Co_2-benzene with a diameter of 0.5 nm is investigated. It shows a magnetic anisotropy in the order of 0.1 eV per molecule, large enough to store permanently one bit of information at temperatures considerably larger than 4 K. A similar performance can be expected, if cobalt dimers are deposited on graphene or on graphite. It is suggested that the subnanometer bits can be written by simultaneous application of a moderate magnetic and a strong electric field.
@article{arxiv.0906.4645,
title = {Co dimers on hexagonal carbon rings proposed as subnanometer magnetic storage bits},
author = {Ruijuan Xiao and Daniel Fritsch and Michael D. Kuz'min and Klaus Koepernik and Helmut Eschrig and Manuel Richter and Knut Vietze and Gotthard Seifert},
journal= {arXiv preprint arXiv:0906.4645},
year = {2015}
}