Two-Dimensional Magnetic Materials for the Next Generation of Functional Device Platforms (2DMagnete)

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Magnetism is perhaps the oldest known physical phenomenon of entirely quantum mechanical origin. From the early studies performed by William Gilbert in his 1600 monograph De Magnete, through to current magnet hard-drive technology using spintronics concepts, several open questions still remain on the limit of magnetism at truly two-dimensional (2D) magnets. This is an intrinsic problem pointed out more than 70 years ago by pioneers in the field such as Louis Néel, Lev Landau or Lars Onsager but still without a plausible solution. Nowadays with the advent of different computational simulation techniques, and experimental approaches, we have the opportunity to tackle this cutting-edge problem with fundamental and technological implications in a real live-basis. The 2017 breakthroughs in discovery of 2D magnetism in monolayer semiconductor crystals (e.g. CrI3) and observation of layer-dependent magnetic phases (e.g. antiferromagnetic or ferromagnetic) open up new paradigms in fundamental science and device technologies. These compounds have enormous potential for magneto-electronics, as well as combining logic and memory for high-performance computing. One game-changing idea is to develop integrated 2D-magnets into selected matrices as smart hybrids with tailored functionalities. Such lightweight materials will have transformative applications in electromagnetic interference shielding (e.g. reduce electromagnetic pollution), low-energy data storage (e.g. better hard-drives), and ultralow-power switching (e.g. smarter health monitoring sensors). Their atomically thin nature will also enable unprecedented manipulation of magnetic properties by non-magnetic means, such as via electric fields or mechanical strain. The van der Waals (vdW) nature of these magnets enables arbitrary design of heterojunctions and devices, without lattice-matching constraints, formed either between different magnets or between magnets and other 2D materials. According to Nobel laureate Andre K. Geim, "the choice of possible vdW structures is limited only by our imagination". Thus, the discovery of 2D magnets combined with interfacial engineering capabilities breaks new ground in the fundamentals of magnetism, with unprecedented control and new functionality. In this project we will: (1) propose focused theory developments to elucidate the magnetic properties of intrinsic vdW materials to groundbreaking advances in device platforms. This is triggered by the ultimate question: "What is the limit of magnetism in an atomic layer material and how to manipulate it?" Long-searched but only recently discovered, truly 2D magnetic materials could enable a revolution on how information data is accessed, understood and stored. How they work is completely unknown. We aim to show how this phenomenon occurs and how to control it. Doing so would bridge the gap across different length scales at finite temperature of a radical new class of magnetic materials. This will lead to a scientific breakthrough in the understanding of low-dimensional magnets and their integration with optics and electronics in a cheap and feasible way in ultra-compact spintronics. (2) To do this we have three steps to take: i) to develop and apply high-throughput techniques to quantum mechanical simulations to predict the best materials that can be truly 2D magnets at temperatures of technological relevance; ii) to benchmark our modelling across different dimensionalities - atomistic (few Å's), mesoscopic (several nm's) and macroscopic (hundreds of micrometer's) - to bridge the modifications of the magnetic phenomena at 2D; and, finally, iii) to investigate the interplay between magnetic properties with external driving forces (electric/magnetic, strain, interfaces) to obtain magnetic control using multiscale methods. Technologically, our proposal would pave the way to materials design of 2D-magnets and goes well beyond the currently possible applications of data storage on magnetic device.