Collective modes in anisotropic double layer systems
  We study collective modes in anisotropic double layer systems. To this end, we derive a zero-$T$ dynamic polarization function for a conductor with a paraboloidal dispersion. Following this, we demonstrate the dependence of the plasmonic modes on the relative orientation, doping, and system anisotropy. 
A. S. Rodin and A. H. Castro Neto
cond-mat.mes-hall