A team at Carnegie Mellon University has overturned a foundational assumption of solid-state physics that had held since 1879: the so-called anomalous Hall effect also appears when the magnetic field lies in the plane of the material – not only perpendicular to it, as textbooks long taught.
What the researchers measured
The Hall effect describes a transverse voltage that arises when a magnetic field deflects moving charge carriers in a conductor. In 1879, Edwin Hall showed that a perpendicular field was required – a principle used ever since in sensors and materials analysis. The group led by Simranjeet Singh and Jyoti Katoch built atomically thin stacks from the quantum material tantalum iridium telluride (TaIrTe₄) and the magnetic compound chromium germanium telluride (Cr₂Ge₂Te₆). In these, an anomalous Hall response could be measured even with a field parallel to the material plane. The results appeared on 3 September 2026 in the journal Nature Materials.
Why it matters for technology
A single sensor could in future detect magnetic fields along several spatial directions – instead of combining multiple components as today. That opens perspectives for more compact magnetic sensors in electronics, vehicles and medical technology, as well as for spintronics, which uses magnetic states to process information.
What remains open
Context matters: the effect has so far only been observed at low temperatures in the lab, on custom-fabricated, nanometre-thin material stacks. Whether it can be reproduced at room temperature and in manufacturable materials remains unclear. Market-ready sensors are therefore still a long way off – the result is first of all a fundamental gain in understanding, not a finished product.
Sources: Carnegie Mellon University (MCS News) · Nature Materials (DOI) · phys.org · ScienceDaily
