2D magnets for spintronic and magnonic applications

Yaroslav Kvashnin
Yaroslav Kvashnin. Photo: Camilla Thulin.

The Swedish Research Council reached a decision on October 31, 2019 on project grants and starting grants for Natural and Engineering Sciences. The Department of Physics and Astronomy is granted 40 840 000 SEK for the period 2020-2023 for in total nine project grants and three starting grants. The projects will begin during 2020.

Project description

Project title: 2D magnets for spintronic and magnonic applications
Main applicant: Yaroslav Kvashnin, Division of Materials Theory
Grant amount: 4 000 000 SEK for the period 2020-2023
Funder: Starting grant from the Swedish Research Council

Current electronic technology is in the limits of its possible miniaturization. In order to make more efficient computers and memory devices, alternatives to silicon-based electronics must be sought. One of the fast-growing fields is spintronics, where the main idea is to use elementary magnetic moments (spin) to perform logical operations and send information. For example, the direction of magnetization can be used to encode information. Therefore, if you have a magnetic material that is as thick as one atomic layer, you will have such a memory density that is impossible to achieve with current technology.

For a long time, 2D magnetism was thought to be impossible. Just two years ago, there were major breakthroughs in this area, when the first 2D magnetic material was found. A monolayer of Crl3 was prepared from its bulk, which is a layered structure in which the layers are weakly coupled through a so-called van der Waals interaction. This result has shaken the scientific community and triggered a considerable activity on these materials and many other monolayered magnetic materials were discovered since then. Most of these materials are only magnetic at very low temperatures, hindering their technological application. However, room temperature magnetism in single-layer VSe2 has recently been reported.

Despite very intense initial examination of these materials, little is known about their basic properties, whether it is possible to tune them in a desirable way and what is their actual potential for applications. The project I propose aims to answer these questions. I will do computer modelling of these materials, starting from the bottom. My idea is to simulate the electronic structure of these materials using so-called first principles calculation. With this method, all the macroscopic properties of the material can be predicted basically from its crystal structure and compared directly with the available experimental data.

The first step in this work is to reproduce and explain available experimental data obtained for pre-existing 2D materials. I will collaborate with a group of Venkata Kamalakar at my department and they will provide further measurements and synthesis of new materials. We will focus on electronic and magnetic excitation spectra, as well as magnetic and transport properties. When the basic properties are reproduced well by the calculations, we will be able to predict how a material will react to certain changes and finally propose new 2D magnetic materials and bring them closer to actual application.