Phys.org June 25, 2024
Flat electronic bands expected to show proportionally enhanced electron correlations are being pursued in d-electron-based systems with crystalline lattices that feature destructive electronic interference. Such flat bands are generically located far away from the Fermi energy, which limits their capacity to partake in the low-energy physics. An international team of researchers (USA – Rice University, Stony Brook University, independent organization, Spain, Austria) showed that electron correlations produce emergent flat bands that are pinned to the Fermi energy. They demonstrated this effect within a Hubbard model, in the regime described by Wannier orbitals where an effective Kondo description arises through orbital-selective Mott correlations. According to the researchers their work shows a novel design principle for Weyl Kondo semimetals in a new setting, viz. d-electron-based materials on suitable crystal lattices, and uncovered interconnections among seemingly disparate systems that may inspire fresh understandings and realizations of correlated topological effects in quantum materials and beyond… read more. Open Access TECHNICAL ARTICLE
Illustration of the bare and emergent flat bands and lattice geometry. Credit: Nature Communications volume 15, Article number: 5242 (2024)