Two-dimensional magnon and spin gases in magnetic Van der Waals heterostructures

Introduction

Dimensionality plays a crucial role in the physical properties of condensed matter systems. In the last century, the optimization of FET technology led to the discovery of a new state of matter, in which quantum mechanics fully confines any electron motion to parallel to the interfaces, i.e., the two-dimensional electron gas (2DEG).

Magnons and Their Importance

Magnons, the elementary excitations of the ground state magnetic order (either ferro, ferri, or antiferromagnetic), also carry spin. In high-quality magnetic materials, magnons enable long-distance electronic spin information transfer.

Current Research Landscape

Magnonics has been studied extensively in magnetic bulk materials or in thin films where several sub-bands are still thermally populated. The challenging major next step is to realize and study magnon and electronic spin transport in the ultimate 2D magnetic regime.

Project Aim

The aim of this ERC Advanced project is to combine and study strictly two-dimensional spin transport in two types of vdW magnets:

1. In a 2D magnon gas (2DMG) in electrically insulating Van der Waals ferro and antiferromagnets.
2. In a 2D spin gas (2DSG) in proximity-induced magnetic graphene.

Methodology

To achieve this aim, I will:

1. Fabricate high-quality 2D vdW materials, heterostructures, and devices.
2. Realize and study spin transport in a two-dimensional magnon gas (2DMG).
3. Realize and study a two-dimensional spin gas (2DSG) in magnetic graphene.
4. Develop new spintronics functionalities in hybrid 2DMG and 2DSG heterostructures.

Expected Outcomes

This project will open a regime that has not been explored before. Magnon-magnon, magnon-phonon, and magnon (electronic) spin interactions in 2D will lead to phenomena that are either difficult to realize in 3D, such as hydrodynamic spin current flow and self-oscillations, or have not yet been anticipated at all.

Impact on Spintronics

2DMG and 2DSG controlled by gates and, possibly, operating at room temperature will enrich the vdW spintronics and provide new strategies for information technology, including heat management.