A German-Japanese research team involving the University of Augsburg has made a significant breakthrough in the use of antiferromagnets. For the first time, the team has succeeded in writing magnetic information using only ultrashort laser pulses—without the need for electric currents or magnetic fields.

Antiferromagnetic materials are considered promising for the next generation of data storage devices because they react particularly quickly and are insensitive to external disturbances. Until now, however, their application has been limited because their magnetic states are difficult to control precisely.

The research team led by experimental physicist Prof. Dr. István Kézsmárki has now developed a new method in which it is not the polarization of the light, but its direction of propagation ("pulse"), that is used for control. Through targeted irradiation, it is possible to switch between different magnetic states and write information. Furthermore, this information can also be read out using purely optical means. The paper is published in the journal Nature Materials.

Data storage technology of the future
The method operates in the telecommunications wavelength range and is therefore compatible with existing optical networks. In the future, it could enable a direct link between optical communication and magnetic data storage—faster and with significantly lower energy consumption.

Furthermore, the researchers were able to demonstrate that complex magnetic patterns can be selectively written into the material and stored stably. By repeatedly switching the material using laser light, the information is retained permanently (nonvolatile), which is a key requirement for practical storage technologies.