Wavelength-selective spin-current generator using infrared plasmonic metamaterials

A subwavelength plasmonic absorber is an ideal platform for absorbing light locally at a desired wavelength. Here, we demonstrate wavelength-selective spin current generation by combining plasmonic absorbers with Pt/yttrium-iron-garnet spintronic devices. These devices are widely used for investigating spin-current phenomena, such as the spin Seebeck effect. At the resonance of the plasmonic absorber in the mid-infrared regime, enhanced spin-current signals are recorded. The observed light-induced spin current can be attributed to both the spin Seebeck effect and photo-spin-voltaic effect. Our results open new prospects for using plasmonic absorbers to bridge nanophotonics and spintronics in numbers of optospintronic applications. (C) 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license.