Fig. 6

The information entropy definition for the information metamaterials. a and b The information system composed of metasurfaces, transmitters and receivers. (from Fig. 1 of Ref. [59]). c The adjacent code group possibility. (from Fig. 1 of Ref. [59]). d The illustration of the geometrical entropy and physical entropy. (from Fig. 1 of Ref. [59]). e-f The randomly-changing process on a 1-bit coding metasurface. (from Fig. 4 of Ref. [59]). g The variation trend of the geometrical entropy and physical entropy. (from Fig. 4 of Ref. [59]). Reproduced with permission from Ref. [59] under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License. Copyright 2016, Springer Nature