Phys.org March 28, 2019
Based on their previous discovery that the “electric field” component of a terahertz pulse plays a key role in the terahertz magnetization modulation of semiconductor-based ferromagnetic materials, researchers in Japan embedded MnAs ferromagnetic nanoparticles in a GaAs host matrix. They observed a large modulation up to 20% of the magnetization of the nanoparticles with terahertz pump pulse irradiation. They found that the modulation is induced by the electric-field component of the terahertz pulse via spin-carrier interactions. The results will lead to an ultrafast coherent magnetization reversal within a picosecond, which will be an essential technique for ultrahigh-speed spintronics…read more. TECHNICAL ARTICLE
A terahertz pump pulse is focused on the surface of a semiconductor sample embedded with ferromagnetic nanoparticles, and a probe pulse detects the ‘excited’ dynamics. A large modulation of up to 20 percent of the magnetization was observed with terahertz pump pulse irradiation. Credit: Ohya Laboratory