Plasmon-induced transparency in terahertz metamaterials

The quantum phenomena of electromagnetically induced transparency (HIT) or plasmonic analogue of electromagnetically induced transparency (PIT) can be mimicked in the classical resonators, leading to a unique way to explore the coherent coupling mechanism in metamaterial systems. Various metamaterial structures have been proposed to excite and manipulate the PIT effect with flexibility and performance with geometry-controllable, polarization-independent, broadband-transparency and active-modulated characteristics. These in turn promise the fascinating functionalities and applications of the PIT effects, such as slow-light components, nonlinear devices and high-sensitivity sensors. Here, we present a review on the progress in developing the PIT effect in terahertz metamaterials over the past few years.