IntroductionProgrammable metasurfaces (PMs)1, which are also called reconfigurable intelligent surfaces (RISs)2,3,4,5,6,7,8,9 in the communications community, are artificial planar structures that can dynamically control electromagnetic (EM) waves, reshaping the wavefronts and creating diverse scattering patterns. These advanced field-manipulation capabilities not only facilitate signal modulations but also enable communication and sensing systems to achieve adaptive and intelligent wireless env...