  We present a metamaterial that acts as a strongly resonant absorber at
terahertz frequencies. Our design consists of a bilayer unit cell which allows
for maximization of the absorption through independent tuning of the electrical
permittivity and magnetic permeability. An experimental absorptivity of 70% at
1.3 terahertz is demonstrated. We utilize only a single unit cell in the
propagation direction, thus achieving an absorption coefficient $\alpha$ = 2000
cm$^{-1}$. These metamaterials are promising candidates as absorbing elements
for thermally based THz imaging, due to their relatively low volume, low
density, and narrow band response.
