Kagome superconductors’ quantum magnetic moments revealed with tin impurities

Researchers at Shanghai Jiao Tong University and the University of California Santa Barbara deliberately introduced tin impurities into kagome superconductors to reveal previously hidden quantum magnetic moments. The work demonstrates that vanadium and titanium ions within these materials both exhibit a 2+ valence, resulting in similar itinerant carrier densities, while differences in electron count manifest as fluctuating ionic magnetic moments. Due to the materials' frustrated lattice geometry, these local moments proved difficult to observe until the team relieved the frustration with nonmagnetic impurities, finding a systematic increase in magnetic susceptibility as impurity levels rose. This discovery suggests a shift from understanding these superconductors solely…