Electronic correlations and competing orders in multiorbital dimers: A cluster DMFT study

摘要: We investigate the violation of first Hund's rule in 4$d$ and 5$d$ transition metal oxides that form solids dimers. Bonding states within these dimers reduce magnetization such materials. parametrize dimer formation with realistic hopping parameters find not only regimes, where system behaves as a Fermi liquid or Peierls insulator, but also strongly correlated regions due to coupling its competition formation. The electronic structure is investigated using cluster dynamical mean-field theory for two-plane Bethe lattice two orbitals per site $3/8$-filling, three electrons dimer. It reveals dimer-antiferromagnetic order high-spin (double exchange) state low-spin (molecular orbital) state. At crossover region we observe suppression long-range magnetic order, fluctuation enhancement renormalization electron masses. certain interaction strengths becomes an incoherent antiferromagnetic well defined local moments.