Using perturbative QED we show that, while the retarded dispersive force between an electrically polarizable atom and a magnetically polarizable one is proportional to 1/r8, where r is the distance between the atoms, the non-retarded force is proportiaonal to 1/r5. This is a rather surprising result that should be compared with the dispersive van der Waals force between two electrically polarizable atoms, where the retarded force is also proportional to 1/r8, but the non-retarded force is proportional to 1/r7.
@article{arxiv.hep-th/0007190,
title = {The non-retarded dispersive force between an electrically polarizable atom and a magnetically polarizable one},
author = {C. Farina and F. C. Santos and A. C. Tort},
journal= {arXiv preprint arXiv:hep-th/0007190},
year = {2007}
}