Optical non-reciprocity in magnetic structures related to high-Tc   superconductors
  Recent neutron scattering [1,2], and optical measurements [3,4] have detected evidence in underdoped cuprate superconductors for a phase transition near the pseudogap onset temperature T* to a time reversal-breaking state. The neutron scattering indicates antiferromagnetic ordering, while it is often assumed that optical polarization rotation requires at least a weak ferromagnetic component. In this note we identify several antiferromagnetic structures, compatible with neutron scattering data, that allow intrinsic polarization rotation through the magnetoelectic effect. 
J. Orenstein
cond-mat.str-el cond-mat.supr-con