23FUN07 Quantum anomalous Hall effect materials and devices for metrology

The Quantum Hall effect (QHE) is the foundation for the realisation of the primary resistance standard (PRS), representing the “gold standard” in electrical metrology. QHE devices currently require low temperatures and high magnetic fields, impeding their adoption beyond national metrology institutes. The Quantum anomalous Hall effect (QAHE) provides an opportunity to overcome these limitations, whilst maintaining the unsurpassed accuracy expected of PRS. Greater knowledge of QAHE devices is important to accelerate the development of a ‘quantum electrical metrology toolbox’ for universal adoption of quantum electrical SI standards. This project will grow, characterise, and evaluate thin films for QAHE, and devices fabricated from them leading to a detailed metrological assessment from sub-K to above 1 K, currents from below 100 nA to above 1 µA and over a wide range of external magnetic fields up to several Tesla.