  We report on the observation of optical spin-controlled modes from a
quasicrystalline metasurface as a result of an aperiodic geometric phase
induced by anisotropic subwavelength structure. When geometric phase defects
are introduced in the aperiodic structured surface, the modes exhibit
polarization helicity dependence resulting in the optical spin-Hall effect. The
radiative thermal dispersion bands from a quasicrystal structure were studied
where the observed bands arise from the optical spin-orbit interaction induced
by the aperiodic space-variant orientations of anisotropic antennas. The
optical spin-flip behavior of the revealed modes that arise from the geometric
phase pickup was experimentally observed within the visible spectrum by
measuring the spin-projected diffraction patterns. The introduced ability to
manipulate the light-matter interaction of quasicrystals in a spin-dependent
manner provides the route for molding light via spin-optical aperiodic
artificial planar surfaces.
