Creating building blocks for atomic-scale electronics

Interfaces in oxide materials offer amazing opportunities for fundamental and applied research, giving a new dimension to functional properties, such as magnetism, multiferroicity and superconductivity. Ferroelectric domain walls recently emerged as a new type of interface, where the dynamic characteristics of ferroelectricity introduce the element of spatial mobility, allowing for the real-time adjustment of position, density and orientation of the walls. This mobility adds an additional degree of flexibility that enables domain walls to take an active role in future devices and hold great potential as functional 2D systems for electronics. Up to now, application concepts rely on injecting and deleting domain walls in micrometer-size devices to control electric conductivity. While this approach achieves a step beyond conventional interfaces by utilizing the wall mobility, it does not break the mould of classical device architectures. Completely new strategies are required to functionalize the versatile electronic properties and atomic-scale feature size of ferroelectric domain walls. ATRONICS will establish a new conceptual approach for developing domain-wall-based technology. At the length scale of only a few atoms, we will use individual walls in improper ferroelectrics to emulate key electronic components such as diodes, transistors and logic gates. Crucially, as the functionality of the components is intrinsic to the domain walls, the walls themselves are the devices, instead of the previous approach of writing and erasing domain walls within a much larger classical device architecture. Beyond demonstrating individual devices, we will integrate multiple domain-wall devices, and develop quasi-2D circuitry and networks with a higher order of complexity then is currently achievable. ATRONICS will represent a major advancement in 2D functional materials for future technologies and play an essential role in the transition from nano- to atomic-scale electronics.