2022/11/02 by Xujia Gong, Wei Wang, Gong, Xujia +11
Earth and Planetary Sciences · Physics and Astronomy · #Advanced Condensed Matter Physics #FOS: Physical sciences #Geological and Geophysical Studies #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2211.00811
openalex publication_date 2022/11/02 · openalex created_date 2023/02/14 · openalex updated_date 2026/07/28
First-principles calculations and simulations are conducted to clarify the nonmagnetic insulating ground state of the honeycomb lattice compound Na2RuO3 with 4d4 electronic configuration and explore the evolutions of crystal structure and electronic property under pressure. We reveal that individual Coulomb correlation or spin-orbit coupling (SOC) effect cannot reproduce the experimentally observed nonmagnetic insulating behavior of Na2RuO3, whereas the Coulomb correlation enhanced SOC interactions give rise to an unusual spin-orbital-entangled J = 0 nonmagnetic insulating state, which contrasts with the SOC assisted Mott insulating state in d5 ruthenates and iridates. Furthermore, a pressure-induced structural dimerization transition has been predicted around 15-17.5 GPa. The honeycomb lattice of the high-pressure dimerized phase features with parallel pattern of the short Ru-Ru dimers aligning along the crystallographic b direction. Accompanied with the structural dimerization, the electronic structure shows striking reconstruction by formation of molecular orbitals. Interestingly, the cooperation of Coulomb correlation together with SOC can realize a nonmagnetic insulating state in the high-pressure dimerized phase. The d4 ruthenate Na2RuO3 with honeycomb lattice will provide a new platform to explore unusual physics and rich phase diagram due to the delicate interplay of lattice degree of freedom, electron correlations, and SOC interactions.