Seeing magnons at spin-to-charge conversion interfaces

Semiconductor devices have revolutionised science and technology in the past decades. They are based on the ability to control the transport of electron charges on the micrometer, and increasingly the nanoscale. The continuous size scaling of transistors - the building blocks of logic devices - is reaching a bottleneck, with heat management and speed reaching physical limits. Spintronic devices is a class of devices which utilises the spin of the electron in addition to its charge, which are believed to have the potential to overcome current challenges in electronics. A way to achieve spin transport is based on the generation and propagation of magnons, spin waves which carry spin momentum. These spin currents can be converted to charge currents at interfaces of magnon generating magnetic materials, with heavy metals such as platinum, where they are driven by temperature gradients. Understanding the phenomena at the charge-to-spin and spin-to-charge conversion at this interface is fundamental for the newly emerging fields of thermal spintronics and spin caloritronics and the design of new electronic devices.

In this project we propose a method to detect and map magnons, by exploiting the ground-breaking capabilities of modern state-of-the-art electron microscopes. This project will provide a new way of studying the fundamentals of magnetic ordering and spin wave excitations in a variety of materials and device structures. Combined with the added wealth of information that analytical electron microscopy can provide such as local atomic structure and chemistry this methodology will provide a complete picture of magnetic and electronic properties of materials and devices.