Schematic of a spintronic trilayer with added dielectric cavity, grown on 0.5 mm of sapphire (Al2O3). The near-infrared pump pulse, incident through the substrate, is partially absorbed in the metallic layers, launching a spin current from the ferromagnetic (FM) layer into the nonmagnetic (NM) layers. The inverse spin Hall effect converts this ultrashort out-of-plane spin current into an in-plane charge current resulting in the emission of THz radiation into the optical far-field. A weak in-plane magnetic field (B) determines the magnetization direction and the linear polarization of the emitted THz field.
Congratulations to third year CDT PGR Rosamund Herapath for her recent publication of Impact of pump wavelength on terahertz emission of a cavity-enhanced spintronic trilayer in Applied Physics Letters.
In this paper, the authors enhance the THz generation of a novel, thin-film THz emitter by adding a set of dielectric overlayers. In doing so, they not only increase the intensity of the THz emitter by a factor of 4 in intensity, but also reduces the amount of IR pump beam transmitted (This will enable the emitter to be used within delicate systems).
She presented her findings in December 2018 at University of Warwick.