Three-dimensional microcoils as terahertz metamaterial with electric and magnetic response

A metamaterial consisting of three-dimensional submillimeter solenoidal coils is presented. The structures have been fabricated by an automated wire-bonding technique and are characterized by terahertz time-domain spectroscopy and numerical simulations. We demonstrate the excitation of electric and magnetic resonances in the microcoils at frequencies between 0.05 and 0.6 THz. The implementation of these microstructures provides a promising route for the design of nonplanar and intrinsically chiral metamaterials for gigahertz to terahertz frequencies.