An efficient way to reduce losses of left-handed metamaterials
  We propose a simple and effective way to reduce the losses in left-handed metamaterials by manipulating the values of the effective parameters R, L, and C. We investigate the role of losses of the short-wire pairs and the fishnet structures. Increasing the effective inductance to capacitance ratio, L/C, reduces the losses and the figure of merit can increase substantially, especially at THz frequencies and in the optical regime. 
Jiangfeng Zhou, Thomas Koschny and Costas M. Soukoulis