Electrons Slow to a Crawl in Fe5GeTe2 Magnetic Material

Researchers at the University of Chicago Pritzker School of Molecular Engineering discovered that electrons in the magnetic material Fe5GeTe2 enter a charge-ordered state where they move collectively in quantum lockstep and slow to a crawl. Published on August 14, 2026, in Science Advances, the study reveals that this coherent response persists up to approximately 100 kelvins and features a surprisingly flat electronic band structure. Led by Assistant Professor Shuolong Yang and postdoctoral scholars Gabriele Berruto and Qiang Gao, the team utilized angle-resolved photoemission spectroscopy with a microfocused ultraviolet laser to map the electronic band structure of Fe5GeTe2. Their findings demonstrate that strong electron interactions create both a flat electronic band and an unexpected charge order, contradicting existing theoretical models of the material's magnetic behavior. The discovery highlights a complex quantum many-body phenomenon where millions of electrons interact and synchronize rather than acting independently. This collective behavior suggests that internal magnetic interactions differ significantly from current theoretical predictions, opening new pathways for fundamental condensed matter physics research. The findings offer potential applications in developing novel quantum memory devices by allowing the material to switch between distinct electronic and magnetic phases using light instead of conventional electrical methods. Future research will focus on testing whether this unique electronic behavior survives down to a single atomic layer and determining if the effect can operate at substantially higher temperatures.