  The creation of wave-dynamic illusion functionality is of great interests to
various scientific communities, which can potentially transform an actual
perception into the pre-controlled perception, thus empowering unprecedented
applications in the advanced-material science, camouflage, cloaking, optical
and/or microwave cognition, and defense security, etc. By using the space
transformation theory and engineering capability of metamaterials, we propose
and realize a functional ghost illusion device, which is capable of creating
wave-dynamic virtual ghost images off the original object's position under the
illumination of electromagnetic waves. The scattering signature of the object
is thus ghosted and perceived as multiple ghost targets with different
geometries and compositions. The ghost-illusion material, being inhomogeneous
and anisotropic, was realized by thousands of varying unit cells working at
non-resonance. The experimental demonstration of the ghost illusion validates
our theory of scattering metamorphosis and opens a novel avenue to the
wave-dynamic illusion, cognitive deception, manipulate strange light or matter
behaviors, and design novel optical and microwave devices.
