Magnonics

Magnonics is an emerging field of modern magnetism, which can be considered a subfield of modern solid-state physics. Magnonics combines the study of waves and magnetism. Its main aim is to investigate the behaviour of spin waves in nano-structured elements. In essence, spin waves are a propagating re-ordering of the magnetisation in a material and arise from the precession of magnetic moments. Magnetic moments arise from the orbital and spin moments of the electron; most often, it is this spin moment that contributes to the net magnetic moment.

Following the success of the modern hard disk, there is significant current interest in future magnetic data storage and using spin waves for things such as 'magnonic' logic and data storage. Similarly, spintronics aims to utilize the inherent spin degree of freedom to complement the already successful charge property of the electron used in contemporary electronics. Modern magnetism is concerned with deepening the understanding of the behaviour of the magnetisation on very small (sub-micrometre) length scales and very fast (sub-nanosecond) timescales, and how this can be applied to improving existing or generating new technologies and computing concepts. A magnon torque device was invented and later perfected at the National University of Singapore's Electrical & Computer Engineering department, which is based on such potential uses, with results published on November 29, 2019, in Science.