Coherent and incoherent metamaterials and the order-disorder transitions
  We demonstrate a new class of "coherent" metamaterials, where a regular ensemble of meta-molecules shows a collective, i.e. coherent, narrow band resonant response, while disordering the ensemble leads to broadening and eventually disappearance of the resonance. We draw parallels between the observed collective behavior of meta-molecules and the Mossbauer effect and notice certain remarkable similarities with the phase transitions of ferromagnetic systems. 
Nikitas Papasimakis, Vassili A. Fedotov, Yuan Hsing Fu, Din Ping Tsai,   Nikolay I. Zheludev