Primordial Metamaterials

The electromagnetic response of materials serves as the foundation for a broad range of vital applications, including but not limited to imaging, sensing, as well as classical and quantum communications. Here we demonstrate, theoretically and experimentally, a fundamentally new regime of electromagnetic material response originating from inherent material nonlocality, leading to effective ``spooky action at a distance''. We show that by structuring materials on the scale of their inherent nonlocality, it becomes possible to reveal the ``primordial'' nonlocal response of the components and design materials with strong overall nonlocality, easily detectable at room temperatures and in realistic (lossy) materials. Designer primordial nonlocality offers a new dimension in controlling light-matter interactions.