Dynamical electric and magnetic metamaterial response at terahertz frequencies.

TitleDynamical electric and magnetic metamaterial response at terahertz frequencies.
Publication TypeJournal Article
Year of Publication2006
AuthorsWJ Padilla, AJ Taylor, C Highstrete, M Lee, and RD Averitt
JournalPhysical Review Letters
Volume96
Issue10
Start Page107401
Date Published03/2006
Abstract

Utilizing terahertz time domain spectroscopy, we have characterized the electromagnetic response of a planar array of split ring resonators (SRRs) fabricated upon a high resistivity GaAs substrate. The measured frequency dependent magnetic and electric resonances are in excellent agreement with theory and simulation. For two polarizations, the SRRs yield a negative electric response (epsilon < 0). We demonstrate, for the first time, dynamical control of the electrical response of the SRRs through photoexcitation of free carriers in the substrate. An excited carrier density of approximately 4 x 10(16) cm(-3) is sufficient to short the gap of the SRRs, thereby turning off the electric resonance, demonstrating the potential of such structures as terahertz switches. Because of the universality of metamaterial response over many decades of frequency, these results have implications for other regions of the electromagnetic spectrum.

DOI10.1103/physrevlett.96.107401
Short TitlePhysical Review Letters