Negative refractive index in symmetric cut-wire pair metamaterial

摘要

Plasmonic metamaterial with a negative refractive index is achieved in a periodical symmetric cut-wire pair without any structural asymmetry. The main control parameter is the lateral lattice size. The designed structure presents two discrete resonance modes due to hybridization. The electric resonance depends strongly on the structural parameter, while the magnetic resonance remains unchanged with this parameter. The hybridization scheme can be inverted by increasing the lateral lattice width. Theoretical and experimental results demonstrate a negative refraction index for the designed structure when the electric resonance frequency occurs below the magnetic one. This spatial arrangement presents many advantages since it is easier, repetitive and well-adapted for realizations in microwave and optical regimes.