  We propose a design for a plasmonic copper metamaterial with a negative index
of refraction at visible/near-infrared wavelengths. Using numerical
simulations, we demonstrate negative refraction by a copper metamaterial prism,
and perform a parameter extraction technique to verify the sign of the
effective, electric permittivity and magnetic permeability. Our proposed design
has a figure of merit comparable to similar silver-based metamaterials
operating in the visible/near-infrared range. These findings have implications
for the design of low cost plasmonic devices and negative-index metamaterials
in the visible / near-infrared.
