Two-dimensional material shows promise for long-term memory, thanks to slow electrons
A 2D magnetic material exhibits a charge-ordered state in which electrons move collectively and unusually slowly while maintaining quantum coherence The post Two-dimensional material shows promise for long-term memory, thanks to slow electrons appeared first on Physics World .
A research team at the University of Chicago has discovered intriguing properties in the 2D material Fe 5 GeTe 2 that could have potential applications in long-term memory technology. This material, part of the van der Waals magnets class, was found to exhibit unusual behavior due to its slow-moving electrons and flat electronic bands.
Prior research showed that Fe 5 GeTe 2 has multiple structural phases with nearly identical stoichiometry and unique electronic and magnetic properties. This prompted the team to explore questions on the nature of these phases and their potential for information encoding.
Using angle-resolved photoemission spectroscopy (ARPES), the researchers probed the electronic structure and magnetic states of Fe 5 GeTe 2, specifically examining the electronic band structure of different phase regions. They discovered that the flat electronic bands in Fe 5 GeTe 2 were a result of the folding of electronic bands in the Brillouin zone near the Fermi level.
This led to a Kondo-like phase, where localized electronic states strongly interact with itinerant states, resulting in quantum coherent flat bands at the Fermi level.
The team was surprised to find this Kondo lattice in a ferromagnetic phase, prompting them to reconsider their understanding of the material's physics. The flat bands in Fe 5 GeTe 2 lead to a spontaneous breaking of space-translation symmetry, forming a new superlattice order that commensurate with the original lattice. This finding provides the first experimental evidence that an interaction-driven flat band can itself drive electronic ordering through flat-band nesting, without requiring Moiré or geometrically frustrated flat-band engineering.
The potential application of this material in memory systems is being explored by using a micro-focused laser to switch between different phases of Fe 5 GeTe 2, including the discovered Kondo-like phase. The researchers aim to utilize the many-body physics for real memory operations, though the material's quantum effects have only been realized at ultralow temperatures so far.
Further fundamental work is ongoing to understand the exact nature of the Kondo-like phase and its potential for topological properties and structural defects.
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