Gap Generation in Topological Insulator Surface States by   non-Ferromagnetic Magnets
  It is shown that, contrary to the naive expectation, single particle spectral gaps can be opened on the surface states of three dimensional topological insulators by using commensurate out- and in-plane antiferromagnetic or ferrimagnetic insulating thin films. 
L\'aszl\'o Oroszl\'any, Alberto Cortijo
cond-mat.mtrl-sci cond-mat.mes-hall