A Quantum Tango between Magnons and Phonons

Changes in information storage technologies reflect the increasing complexity of societies [1]. Five thousand years ago, the progress of agricultural civilizations in Mesopotamia drove the development of the cuneiform script—wedge-shaped carvings on clay tablets. Today, innovative strides of the information society have led to spintronic devices that “carve” 0’s and 1’s into the spin states of electrons in magnetic materials. But our growing hunger for data calls for even denser and faster storage methods. Magnonics is a promising next-generation approach in which quantized spin waves, or magnons, are used to carry information. Magnons are generally hard to manipulate, but a study by Felix Godejohann of the Technical University of Dortmund, Germany, and colleagues could lead to new ways to control magnons via their coupling to acoustic vibrations, or phonons, in a material [2]. The researchers engineered a grooved magnetic structure that allowed them to study and optimize various factors affecting magnon-phonon coupling, achieving an unprecedented coupling strength.