Magnetic response of split ring resonators at terahertz frequencies

We investigate numerically the electric and the magnetic response of the split-ring resonators (SRRs) for different electromagnetic (EM) field polarization and propagation directions. We have studied the current density J of circular and rectangular SRRs at THz frequencies. At low frequencies, J is confined to the edges of the SRRs, while at high frequencies J is all over the width of the wire. The diamagnetic response of the SRRs is also examined. Finally, the role of losses and the magnetic resonance frequency are studied as the size of the SRRs becomes less than 100 nm. (C) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.