Twist-angle dependent circular dichroism instacked Archimedean planar metamaterialswithout a layer distance

Stacked planar chiral metamaterials which combine the fabrication convenience of planar metamaterials and good chirality of stereo metamaterials have recently drawn a lot of attention. In this paper, we present a study on the CD performance in the double-layer and multi-layer closely stacked Archimedean planar metamaterials (SAPMs), which will simultaneously support localized modes in the interface of two spirals and non-localized conductive modes in the whole structure, as well as show particular twist-angle dependent CD performance and broadband CD performance due to the coaction of localized modes and non-localized modes. We give reasonable explanations on the CD performance of SAPMs by employing the plasmonic Lagrange model and the equivalent model. We also discuss the optimization of structural parameters and application challenge of our proposed model.