Survival of the metallic state in a single-hole multiband p-orbital molecular system
K. Matsui, R. A. Klein, N. Yoshikane, J. Arvanitidis, Matjaž Gomilšek, Urh Klopčič, S. Kawaguchi, H. Yamaoka, N. Hiraoka, H. Ishii, Q. Zhang, S. Mori, H. Ishibashi, Y. Kubota, Craig M. Brown, Denis Arčon, and Kosmas Prassides, Nat. Commun. 17, 4599 (2026)
Researchers from the Jožef Stefan Institute and the Faculty of Mathematics and Physics, University of Ljubljana, together with collaborators from Japan, the USA, and Greece, have reported the discovery of a robust metallic state in the molecular material Yb2CsC60. The study has been published in Nature Communications.
The work explores how strong electronic correlations behave in fullerene-based molecular solids containing a single “hole” in multiorbital electronic states. Using synchrotron X-ray diffraction, neutron scattering, Raman spectroscopy, NMR, X-ray absorption spectroscopy, and first-principles calculations, the team demonstrated that Yb2CsC60 remains metallic without undergoing a Mott transition.
The results reveal a remarkable analogy between correlated molecular p-electron systems and transition-metal d-electron materials, providing new insight into Hund-coupling physics and strongly correlated quantum matter. The newly synthesized orthorhombic fulleride may also open pathways toward discovering unconventional superconductivity in related molecular systems.
