We predict that neutral graphene bilayers are pseudospin magnets in which the charge density-contribution from each valley and spin spontaneously shifts to one of the two layers. The band structure of this system is characterized by a momentum-space vortex which is responsible for unusual competition between band and kinetic energies leading to symmetry breaking in the vortex core. We discuss the possibility of realizing a pseudospin version of ferromagnetic metal spintronics in graphene bilayers based on hysteresis associated with this broken symmetry.
@article{arxiv.0707.1530,
title = {Pseudospin Magnetism in Graphene},
author = {Hongki Min and Giovanni Borghi and Marco Polini and A. H. MacDonald},
journal= {arXiv preprint arXiv:0707.1530},
year = {2008}
}