Terahertz Laser Pulses Revolutionize Ferromagnetism for High-Speed Computing.
Researchers have used terahertz light pulses to induce ferromagnetism in a crystal at temperatures far above its normal transition temperature, paving the way for optically controlled memory and computing devices with higher speed and efficiency. Using pulses just hundreds of femtoseconds long, a ferromagnetic state was induced at high temperature in the rare-earth titanate YTiO3 which persisted for many nanoseconds after the light exposure. The intense light pulse is designed to ‘shake’ the material’s atoms in a coordinated way, allowing the electrons to align their spins.