title: Second-harmonic generation from magnetic metamaterials.
abstract: We observe second-harmonic generation from metamaterials composed of split-ring resonators excited at 1.5-micrometer wavelength. Much larger signals are detected when magnetic-dipole resonances are excited, as compared with purely electric-dipole resonances. The experiments are consistent with calculations based on the magnetic component of the Lorentz force exerted on metal electrons-an intrinsic second-harmonic generation mechanism that plays no role in natural materials. This unusual mechanism becomes relevant in our work as a result of the enhancement and the orientation of the local magnetic fields associated with the magnetic-dipole resonances of the split-ring resonators.
authors.affiliation: Institut für Angewandte Physik, Universität Karlsruhe (TH), Wolfgang-Gaede-Strasse 1, D-76131 Karlsruhe, Germany.
authors.forename: Matthias W
authors.initials: MW
authors.lastname: Klein
authors.forename: Christian
authors.initials: C
authors.lastname: Enkrich
authors.forename: Martin
authors.initials: M
authors.lastname: Wegener
authors.forename: Stefan
authors.initials: S
authors.lastname: Linden