High Q-factor and large group delay at microwave wavelengths via electromagnetically induced transparency in metamaterials

We report on our numerical work concerning a planar metamaterial exhibiting classical electromagnetically induced transparency (EIT). Using a structure with two asymmetric short strips, we demonstrate that an EIT-like resonance with a high quality factor can be achieved and this high quality factor leads to a large group index of the order of 700. The operation of metamaterial at low temperatures is anticipated to be a promising path towards low-loss metamaterials since nonradiative losses are strongly suppressed. By decreasing temperature from 300 K to 100 K, a controlled behavior with a 26% increase in the quality factor of the resonance and an 85% increase in the group index was observed. (c) 2012 Optical Society of America