Role of Magnetic Plasmon Resonance in Plasmonic Electromagnetically-Induced Transparency

We find that the magnetic plasmon resonance plays a vital role in plasmonic electromagnetically-induced transparency (EIT) proposed by Zhang et al. [\prl \textbf{101}, 047401 (2008)] as well as the localized surface plasmon polaritons. Based on this picture, the plasmonic EIT control through single optical field is suggested in a modified scheme for active plasmonic switching by simply adjusting the incident angle of the optical field. The tunability of plasmonic EIT in this scheme is exhibited sufficiently.