Researchers from TU Wien designed a method to create extremely strong spin currents using ultra-short laser pulses.
Using computer simulations, the researchers discovered that when short laser pulses hit a thin layer of nickel on a silicon substrate, the electrons accelerate toward the silicon, which builds an electric field on the interface of the two materials. This stops the current, but the spin is still transported. the spin-up electrons move freely, while the spin-down electrons have a much higher probability of being scattered at the nickel atoms. This creates many spin-up electrons in the silicon - effectively creating a spin current in the silicon.