Researchers at the University of Chicago Pritzker School of Molecular Engineering have discovered an unusual quantum state in the two-dimensional magnetic material Fe₅GeTe₂. Using angle-resolved photoemission spectroscopy (ARPES) with a microfocused ultraviolet laser, they observed a «flat band» — a situation where electrons move collectively at unusually low effective speeds while retaining quantum coherence. This finding deviates from existing theoretical predictions about the material’s magnetic interactions. The team suggests that distinct magnetic states within Fe₅GeTe₂ could be used to encode information in a memory storage system. They are currently testing whether a focused laser can switch the material between the quantum many-body phase and other phases, an essential step before any device application can be established. A key advantage is that the observed coherent response persists up to approximately 100 kelvin above absolute zero — significantly warmer than many other quantum materials, though still far from room temperature.
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