Interaction between Metamaterial Resonators and Inter-subband   transitions in Semiconductor Quantum Wells
  We report on the coupling and interaction between the fundamental resonances of planar metamaterials (split ring resonators) and inter-subband transitions in GaAs/AlGaAs quantum wells structures in the mid-infrared. An incident field polarized parallel to the sample surface is converted by the metamaterial resonators into a field with a finite component polarized normal to the surface, and interacts strongly with the large dipole moment associated with quantum well inter-subband transitions. 
Alon Gabbay, John Reno, Joel R. Wendt, Aaron Gin, Michael C. Wanke,   Michael B. Sinclair, Eric Shaner and Igal Brener
physics.optics