Researchers at the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) have developed an innovative method to study ultrafast magnetism in materials. They have shown the generation and application of magnetic field steps, in which a magnetic field is turned on in a matter of picoseconds.

The work has been published in Nature Photonics.

Magnetic fields are fundamental to controlling the magnetization of materials. Under static or slowly varying conditions, a material’s magnetization aligns with the external field like a compass needle. However, entirely new magnetization dynamics emerge when magnetic fields change on ultrafast timescales—faster than the material’s response time.