  Heat generated by spin currents in spintronics-based devices is typically
much less than that generated by charge current flows in conventional
electronic devices. However, the conventional approaches for excitation of spin
currents based on spin-pumping and spin Hall effect are limited in efficiency
which restricts their application for viable spintronic devices. We propose a
novel type of photonic-crystal (PC) based structures for efficient and tunable
optically-induced spin current generation via the Spin Seebeck and inverse spin
Hall effects. It is experimentally demonstrated that optical surface modes
localized at the PC surface covered by ferromagnetic layer and materials with
giant spin-orbit coupling (SOC) notably increase the efficiency of the
optically-induced spin current generation and provides its tunability by
modifying light wavelength or angle of incidence. Up to 100% of the incident
light power can be transferred to heat within the SOC layer and, therefore, to
spin current. Importantly, high efficiency becomes accessible even for
ultra-thin SOC layers. Moreover, surface patterning of the PC-based spintronic
nanostructure allows local generation of spin currents at the pattern scales
rather than diameter of the laser beam.
