Magic cube metamaterials

Abstract

Traditionally, magic cube configurations, which have been employed to mechanically execute diverse and unconventional structural transformations, are capable of significantly boosting versatile electromagnetic responses of reconfigurable metamaterials. However, this idea is still in the initial exploration stage and faces many constraints. Here, we propose magic cube metamaterials with features of high transparency, multi-gradient phase distribution, full polarization, and high information, which manifest 47.58% optical transmittance, a 6-order phase distribution, a 77% fractional operating bandwidth, and 65.23 times information entropy of their planar counterparts. The reflection phase corresponding to coplanar lattice of the metamaterials can be dynamically and omni-directionally controlled via altering their spatial distributions through individually addressing each rotatable meta-particle while maintaining the polarization states. The optically transparent design allows for real-time visual interaction and sequence mapping of the reconfigurable metamaterials. As two proof-of-concept meta-devices, an achromatic metalens with an unchanged focal length and a switchable multi-functional beam generator is demonstrated by simulations and experiments in an ultra-wide band (8.0-18.0 GHz). This work provides an effective alternative for designing reconfigurable metamaterials with high information-entropy properties, paving a new route toward advanced equipment such as active signal processors and information encryption/decryption systems.

Keywords: Dynamic achromatic metalens; Full-polarization operations; Information entropy; Magic cube metamaterials; Switchable beam generator.