Quantum anomalous Hall effect materials and devices for metrology

In electric metrology, the Quantum Hall effect (QHE) is essential for realisation of the primary resistance standard (PRS), on which most basic measurands, including current, resistance, capacitance or electric power, depend on. However, currently QHE devices only function at low temperatures and high magnetic fields, which hinders their widespread implementation. The Quantum anomalous Hall effect (QAHE) could be used to realise the PRS without these limitations as it works without an external magnetic field. However, materials need to be further developed and metrologically validated before SI-traceable QAHE devices can be developed.  These developments are also essential for the development of a ‘quantum electrical metrology toolbox’, which will ultimately benefit the Quantum Technologies Flagship, EU initiative that was created to support quantum technology research and ensures Europe’s competitiveness in the field of quantum technologies.

This project aims to develop new materials for the QAHE, including magnetically doped topological insulators that are interfaced with anisotropic magnetic insulator layers to produce high structural quality materials that have optimised properties for QAHE. These materials will be tested for their electronic, structural, magnetic, and magneto-electronic properties with QAHE devices under different conditions, including temperature and applied magnetic fields to determine the limitations of QAHE. These optimised QAHE devices will be fully metrologically assessed and ensure Europe’s metrological network remains competitive. Additionally, these developments will support the United Nation’s sustainable development goal 9 for industry, innovation and infrastructure.