Search for new promising topological magnets for applications in information technologies
Abstract
Magnetic materials have many uses, e.g. for electricity production, in the transport sector and for information technology. In the latter case, it is common to use oppositely oriented domains of a ferromagnet to store sequences of "0" and "1", the natural the building blocks behind the binary code in hard drives. Miniaturization of this technology has shown impressive results but has almost approached the physical limit of domain stability. In some magnets, however, domains can wrap around single points in space to form so-called skyrmions, which consist of atomic spin and have a size in the nanometer range. Important here, is that they show non-trivial topology for the so-called spin winding. This makes them more stable compared to regular magnetic domains and offers an alternative memory storage with potentially higher energy efficiency and information density, which motivates the ongoing research. Unfortunately, topological magnets often rely on rare elements and complicated energy-intensive synthesis, while also not fulfilling all criteria to be suitable for real-life application, e.g. showing stable magnetism at room temperature and skyrmions with a size below 100 nm as well as being able to host 2 types of skyrmions at the same time to encode the information bits.
This project will explore several new directions and different materials that have a good potential for solving these problems and offering high degree of tunability for applications. Wide range of modern theoretical methods for predicting materials properties will be used for computer design of topological magnets with desired properties, which will be later on verified through collaboration with experimentalists. As a starting point for designing new materials in this project, different known systems with strong magnetism, present at room temperature, will be considered, both inorganic and organic ones. The later will be especially attractive due to easier energy-efficient synthesis and usage of cheap accessible chemical elements. For these starting systems, the problems that need to be solved are i) reducing the size of skyrmions to achieve higher information density and ii) stabilizing skyrmions of, at least, 2 different types to encode binary information sequences. Several strategies will be applied, such as structural and chemical design (e.g.~formation of multilayers with nanometer precision), together with computer simulations to solve these problems and create novel magnetic materials where skyrmions are tailored for robust memory storage and potentially fast computations, enabling real-life applications.
