Researchers at RPTU University Kaiserslautern-Landau have achieved a key experimental breakthrough: For the first time, the spontaneous macroscopic coherence of magnons—the quantized excitations of magnetic materials—has been directly observed. These experiments confirm a central prediction of the theory of magnon Bose-Einstein condensates. Eventually, these findings could open new avenues for signal processing, sensing technologies and information processing. The study has been published in Nature Physics.