Amazing stuff!
"Researchers ... have discovered direct evidence of active flat electronic bands in a kagome superconductor. ...
It focuses the chromium-based kagome metal CsCr₃Sb₅, which becomes superconducting under pressure. ..."
"... Kagome metals, characterized by their two-dimensional lattices of corner-sharing triangles, have recently been predicted to host compact molecular orbitals, or standing-wave patterns of electrons that could potentially facilitate unconventional superconductivity and novel magnetic orders that can be made active by electron correlation effects. In most materials, these flat bands remain too far from active energy levels to have any significant impact; however, in CsCr₃Sb₅, they are actively involved and directly influence the material's properties. ...
"By identifying active flat bands, we've demonstrated a direct connection between lattice geometry and emergent quantum states," ..."
From the abstract:
"In the quest for topology- and correlation-driven quantum states, kagome lattice materials have garnered significant interest for their band structures, featuring flat bands (FBs) from the quantum destructive interference of the electronic wavefunction.
Tuning an FB to the chemical potential could induce electronic instabilities and emergent orders. Despite extensive studies, direct evidence of FBs tuned to the chemical potential and their role in emergent orders in bulk materials remains lacking.
Using angle-resolved photoemission spectroscopy, resonant inelastic X-ray scattering, and density functional theory, we show that the low-energy structure of the Cr-based kagome metal superconductor CsCr3Sb5 is dominated by FBs at the Fermi level.
We also observe low-energy magnetic excitations evolving across the low-temperature transition, largely consistent with the FB shift. Our results suggest that the low-temperature order contains a magnetic origin and that the kagome FBs may play a role in the emergence of this order."
A strange quantum effect could power future electronics (original news release)
Fig. 2: Electronic structure of CsCr3Sb5.
No comments:
Post a Comment