Survival of the metallic state in a single-hole multiband $p$-orbital molecular systemMatsui, Keisuke (Avtor) Gomilšek, Matjaž (Avtor) Klopčič, Urh (Avtor) Arčon, Denis (Avtor) Prassides, Kosmas (Avtor) condensed matter physicsmaterialselectronic propertiescrystal structureStrong correlations and ferromagnetic Hund’s coupling lead to diverse electronic phenomena in transition-metal oxides that sensitively depend on the ▫$d$▫-orbital electron filling. Fullerides, their ▫$p$▫-electron counterparts, exhibit effective antiferromagnetic Hund’s coupling in a different energy range. At half-filling (▫$n = 3$▫, three electrons in triply degenerate orbitals), both ▫$d$▫- and ▫$p$▫-electron systems are Mott insulators due to strong correlations and Hund’s coupling. Away from half-filling, in single-electron/hole (▫$n = 1,5$▫) ▫$d$▫-orbital systems, Hund’s coupling opposes the correlations, reducing the Mott gap and allowing survival of metallicity. Here we report a single-hole multiorbital correlated p-electron system, orthorhombic-structured Yb▫$_2$▫CsC▫$_{60}$▫ comprising pentavalent C▫$_ {60}$▫▫$^{5-}$▫ anions, which also exhibits a robust metallic state with no Mott transition, just like in the metastable single-electron cubic-structured CsC▫$_{60}$▫. We assert that particle-hole symmetry holds well in (▫$n = 1,5$▫) fullerides and that their ▫$p$▫-electron-derived states are analogous to those in ▫$d$▫-orbital solids, providing impetus for further study of these correlated systems.20262026-05-27 13:07:44Članek v reviji182895sl