NEWSROOM

Researchers at the University of Osaka have directly observed a heavy-fermion state forming at the interface between a one-atom-thick ytterbium-copper (YbCu₂) layer and a copper crystal, using intense synchrotron light to probe electron behavior. They identified two distinct states, one confined to the two-dimensional layer and another extending into the three-dimensional substrate, arising from hybridization between localized Yb 4f and mobile conduction electrons.