Unveiling the Electromagnetic Responses of Fourfold Symmetric Metamaterials and Their Terahertz Sensing Capability

We present the tailored terahertz responses via the hybridization of magnetic and electric resonators under normal incidence of electromagnetic wave. These cross-I sandwiched structures enable us to couple out the negative magnetic resonance followed by the effective inductance-capacitance (LC) circuit model, along with the negative electric response contributed by the excitation of diluted Drude metal resonance, thus allowing the realization of negative refraction index with a value of -2.3 at 4 THz. Furthermore, the cross-I sandwiched structures possess the compelling sensing performance based on their remarkable sensitivity and high-quality resonant behavior, holding great potential for practical applications in chemical/biological detection. (C) 2013 The Japan Society of Applied Physics