The ability to manipulate the magnetic properties of a material underlies many applications in everyday life, such as the ability to store information on the hard disk of your computer. So far, this has been achieved using magnetic read/write heads that alter the orientation of magnetic fields in the domains of a material. This provides a contribution to the electrostatic energy, called exchange energy, that encodes information bits.
A group of researchers from Rome's Sapienza University, in collaboration with the Radboud University of Nijmegen and the Politecnico di Milano, has shown that it is possible to change exchange energy directly, without necessarily altering the magnetic structure of the material. Using very short laser pulses (quantifiable in billionths of millionth of a second), an increase in energy exchange has been observed, for a time limited to the duration of the pulse itself, and therefore extremely faster than that obtainable by applying an external magnetic field.
G. Batignani, D. Bossini, N. Di Palo, C. Ferrante, E. Pontecorvo, G. Cerullo, A. Kimel and T. Scopigno* Nature Photonics, doi: 10.1038/NPHOTON.2015.121