Analytical circuit model for split ring resonators in the far infrared and optical frequency range

The article proposes an LC-circuit model for single split ring resonators (SRRs) operating at far infrared and optical frequencies. Taking the effects of magnetic and kinetic inductances as well as gap and surface capacitances into account, we obtain analytical expressions for the resonant frequency of the singly, doubly, and quadruply split SRRs. Comparing the analytical results with numerical simulations, we show that the numerical simulations agree better with the present model than with the models reported previously. We also discuss a size dependent correction to the electron collision frequency which takes into account electron collisions with SRR walls.