CAMIE (Combining Advanced Materials for Interface Engineering)

The challenge we have set ourselves is to find fundamentally new ways to store, manipulate and transport information based on our unique approach to materials integration and interface control.

Electronic applications and their use are increasing at exponential rates with 6% of the global energy consumed by ICT. As anyone who has used an electronic gadget knows, they rapidly get warm. But the heat is a by-product of the way that they use electric currents which is unsustainably dumped into the environment. Electric currents are used to transfer information, to store it, retrieve it and to perform operations. As devices become smaller, the problem increases because the materials become more resistive to currents and generate more heat. The scale of the problem is huge. As an example, Google reports that significant amounts of energy are used to cool their server farms. In 2021, they used ~12 TWhr of electricity, about the same as a small country, and the trend is increasing.

The internet currently has a carbon footprint that is larger than that of the airline industry and is predicted to double from 2020 to 2025. For long-term sustainability we must reduce the consumption of energy in ICT.
Spintronics exploits the magnetic property of electrons (spin) for applications. It offers compelling possibilities for new devices that might function at reduced energy. Pure spin currents transfer spin without transferring charge so that information can be exchanged without the heat a charge current generates. Using electric fields in devices can have great advantages over magnetic fields, including using less energy, but usually magnetism cannot be controlled by electric fields.

Molecular interfaces can be altered by electric fields and ferroelectrics have a polarisation that can be switched electrically hence tuning the behaviour of a magnet when they are connected. A stumbling block to progress is that these different materials require different techniques of preparation and to be useful in ICT they must be thin - of the order of tens of atoms thick. Such thin layers need to be protected during their fabrication and then the different layers combined. The solution requires bespoke designs and breakthroughs in materials science.

The Royce Institute is a key EPSRC investment (£235M) founded to "accelerate the invention and take-up of new material systems that will meet global challenges", driving the UK strategy to increase our ability to compete, not only in science, but in the marketplace. At Leeds we recently installed the Royce Deposition System: a £2.2M suite of chambers each of which is designed to grow a different type of advanced material that requires different deposition methods and environments for processing. The chambers are connected together through ultra-high vacuum tubes so samples can be transferred whilst being protected from the atmosphere and impurities. Crucially, by controlling their interfaces at the atomic level we can grow layers of different materials and bring them together into a single hybrid structure. For example, we can: form 2 dimensional materials with electrical polarisation to control magnets; build molecular thin film interfaces that lead to tuneable emergent magnetic, optoelectronic and superconducting properties; drive magnetic textures using spin currents from topological materials, etc. A complete understanding of these hybrid structures will pave the way to exploitable technology where the initial benefits will enable information processing and storage with less energy, reducing carbon emissions and prolonging battery life.

Our approach has the potential to impact many areas of technology such as data storage, sensors, energy storage, and quantum materials.
 

Project website

https://camie.leeds.ac.uk/