Anomalous band formation in arrays of terahertz nanoresonators.

We investigate band formation in one-dimensional periodic arrays of rectangular holes which have a nanoscale width but a length of 100 µm. These holes are tailored to work as resonators in the terahertz frequency regime. We study the evolution of the electromagnetic response with the period of the array, showing that this dependence is not monotonic due to both the oscillating behavior of the coupling between holes and its long-range character.