Nonlinear gyrotropy in isotropic metamaterials

The paper proposed a metamaterial which chirality can be dynamically induced in a non-chiral medium. This becomes possible in a racemic mixture containing equal amounts of right- and left-handed spirals, in which one type of spirals is either tunable or nonlinear. The authors demonstrated this effect numerically and experimentally for the example of electromagnetic waves scattering on a pair of canonical spirals of different handedness, where one of the spirals contains a nonlinear element.