THz Emission from Spintronic Microstructure

Abstract: Recent advancements in spintronics have opened a new avenue in terahertz (THz) radiation sources that may outperform the traditional contact-based metallic counterparts. Inspired by the generation of broadband spintronic THz signals at the interface of a ferromagnet and ultrawide bandgap semiconductors, here we investigated the generation of THz radiation from micro-structured heterostructures of a metallic ferromagnet (Ni80Fe20) and an ultrawide bandgap semiconductor (AlGaN/GaN) that contains a layer of 2D electron gas. By precisely tailoring the dimension of the subwavelength pillars of a THz device, the micro-structured spintronic THz emitter can achieve up to more than three times higher emission intensity compared to that of the un-patterned counterpart. Our study advances the development of the next generation of spintronic THz sources that allow a tailored emission frequency and intensity control and, further, are compatible with existing integrated wide-bandgap semiconductor circuits.