After the traditional New Year’s coffee had to be cancelled for two years due to corona, the FHI employees were happy to finally come together again with a sparkling drink, finger food, a delicious bratwurst and wonderful weather at the Haber lime tree.

Figure: Lanthanides (here LnRh2Si-Layers) are increasingly important in the use of technology because of their magnetic properties. © FHI / W. Windsor

When photoexcited by an ultrafast laser pulse, antiferromagnets allow direct angular momentum transfer between opposing spins, promising faster functionality than ferromagnets, which are inherently limited because their net angular momentum must be dissipated into the lattice. The process of angular momentum transfer is closely related to the type of magnetic coupling in the system.
In lanthanides, magnetic 4f exchange is mediated indirectly via the conduction electrons (Ruderman-Kittel-Kasuya-Yosida [more...]