Application of metasurface description for multilayered metamaterials   and an alternative theory for metamaterial perfect absorber
  We analyze single and multilayered metamaterials by modeling each layer as a metasurface with effective surface electric and magnetic susceptibility derived through a thin film approximation. Employing a transfer matrix method, these metasurfaces can be assembled into multilayered metamaterials to realize certain functionalities. We demonstrate numerically that this approach provides an alternative interpretation of metamaterial-based perfect absorption, showing that the underlying mechanism is a modified Fabry-Perot resonance. This method provides a general approach applicable for decoupled or weakly coupled multilayered metamaterials. 
Jiangfeng Zhou, Hou-Tong Chen, Thomas Koschny, Abul K. Azad,   Antoinette J. Taylor, Costas M. Soukoulis, John F. O'Hara
physics.optics cond-mat.mtrl-sci