Scientists observe new quantum behavior in superconducting material

Researchers have observed novel quantum behavior in the chromium-based kagome metal CsCr₃Sb₅, marking a significant advance in understanding superconductivity. Kagome metals feature a distinctive lattice geometry of corner-sharing triangles, which theoretically can host flat electronic bands—compact molecular orbitals that influence electron behavior. Unlike most kagome materials where these flat bands lie too far from active energy levels, in CsCr₃Sb₅ the flat bands actively participate in shaping the material’s superconducting and magnetic properties. This discovery confirms theoretical predictions and opens a pathway for engineering exotic superconductivity through precise chemical and structural control. The study, led by scientists from Rice University and Taiwan’s National Synchrotron Radiation Research Center and published in Nature Communications, combined advanced experimental techniques such as angle-resolved photoemission spectroscopy (ARPES) and resonant inelastic X-ray scattering (RIXS) with theoretical modeling. These methods revealed distinct signatures of the flat bands and their role in magnetic excitations, demonstrating