Novel nonlinear chiral metamaterials

We report on a novel metamaterial design based on multi-turn spiral resonators which strongly enhance nonlinear coupling between electromagnetic and mechanical response. The robust fabrication procedures allowed to produce a large number of resonators, suitable for assembling large metamaterials arrays. We experimentally demonstrate a remarkable self-tuning of the electromagnetic resonance, achieved via power-dependent mechanical reconfiguration, dominating over thermal effects. The corresponding compression of the spirals provides a nonlinear chiral response.