University of Chicago finds slow electrons stay quantum coherent

Researchers at the University of Chicago Pritzker School of Molecular Engineering have discovered an unusual behavior in the van der Waals magnet Fe 5 GeTe 2, a material discovered seven years ago.

The team reports that electrons within the material move collectively and unusually slowly while maintaining quantum coherence, a finding that changes current knowledge of the material and unlocks new technological applications, according to Asst. Prof. Shuolong Yang. Using angle-resolved photoemission spectroscopy with a 10-micrometer ultraviolet laser, they observed a “flat band” where electrons exhibit this collective, slow movement. This discovery challenges existing theoretical predictions about the material’s magnetic interactions and suggests potential applications in new memory devices. Fe 5 GeTe 2 Exhibits Slow, Coherent Electrons This unexpected characteristic challenges established theoretical models of magnetic interactions within the material and opens avenues for novel memory technologies.

The team’s findings, published in Science Advances on August 7, 2026, reveal an electronic band that is remarkably flat, indicating a significant reduction in electron velocity. The observation of this flat band was unexpected, as electrons typically move faster within a material when possessing higher energy levels; however, in Fe 5 GeTe 2, the electrons exhibit collective movement at a drastically reduced speed. That’s a quantum many-body phenomenon, and it’s actually a very weird thing.” This collective behavior, likened to a shallow waterfall where water flows slower, signifies a departure from conventional understanding of electron dynamics in similar materials.

The team’s work suggests that the magnetic interactions within Fe 5 GeTe 2 are fundamentally different from those previously predicted by theoretical models. This deviation from established theory necessitates a reevaluation of the material’s magnetic properties, according to Gabriele Berruto, a member of the research team. He stated that the findings suggest the magnetic interactions within the material are different from what theory predicts. The van der Waals nature of Fe 5 GeTe 2, characterized by its atomically thin layers, is crucial to its potential for memory applications, offering advantages over traditional magnetic materials. These layers allow for greater control over the material’s properties and could lead to more efficient and compact memory storage systems.

The team’s experiments have demonstrated coherence up to 100 degrees above absolute zero, a promising result considering that most quantum phenomena require extremely cold temperatures to be observed. Qiang Gao, now at Lawrence Berkeley National Laboratory, emphasized the importance of achieving room-temperature operation for practical applications. “If we eventually want to use it in a memory device, it needs to work at room temperature,” he said. Further investigation is focused on exploring the properties of Fe 5 GeTe 2 when exfoliated down to a single atomic layer, potentially enhancing its performance and stability. The research builds upon the work of the late Peter Littlewood, a distinguished physicist at the University of Chicago, whose contributions to quantum materials research were highly regarded. Yang said, “He was a great theoretical physicist and a leader of quantum materials research at UChicago. We dedicate this paper to him.” The team’s findings represent a significant step forward in understanding the complex behavior of two-dimensional materials and their potential for technological innovation. The observed slow electron movement isn’t simply a reduction in speed, but a fundamentally different mode of electron interaction. The ARPES data revealed that the electrons aren’t behaving as independent particles, but as a collective, coherent entity. This many-body effect is what makes Fe 5 GeTe 2 so unusual and potentially valuable. The flat band structure, indicative of this collective behavior, suggests that the electrons are strongly correlated, meaning their movements are intricately linked. This strong correlation allows them to maintain coherence despite their slow speed, a combination rarely observed in other materials. The implications for memory technology stem from the ability to control and manipulate these slow, coherent electrons. Different magnetic states within the material could represent different bits of information, and the switching between these states, potentially achieved with a laser, would form the basis of a new type of memory device. This device could offer advantages over existing technologies in terms of speed, energy efficiency, and storage density.

The team’s current work on laser-induced switching is a crucial step towards realizing this potential. The ability to reliably and efficiently switch between different quantum phases is essential for creating a functional memory device. The fact that this coherent behavior persists at a relatively high temperature, 100 degrees above absolute zero, is particularly encouraging. While still below room temperature, this represents a significant improvement over many other quantum materials, which require extremely low temperatures to exhibit their unique properties. This higher operating temperature makes Fe 5 GeTe 2 a more practical candidate for real-world applications.

The team’s ongoing research aims to push this temperature even higher, ultimately achieving room-temperature operation, which would be a major breakthrough in the field of quantum materials. This work, supported by the U.S. Department of Energy and the Gordon and Betty Moore Foundation, highlights the growing interest in exploring the potential of two-dimensional materials for next-generation technologies. If we eventually want to use it in a memory device, it needs to work at room temperature. Qiang Gao, Research Scientist at Lawrence Berkeley National Laboratory Source: https://pme.uchicago.edu/news-events/news/discovery-slow-electrons-2d-material-could-lead-new-memory-device Stay currentSee today’s quantum computing news on Quantum Zeitgeist for the latest breakthroughs in qubits, hardware, algorithms, and industry deals. Tags: