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TT: Fachverband Tiefe Temperaturen
TT 27: Correlated Electrons: Other Materials
TT 27.13: Talk
Tuesday, March 19, 2024, 12:45–13:00, H 3010
Study of M3O12 trimers in transition metal cluster Mott insulators — •Vaishnavi Jayakumar1 and Ciarán Hickey1,2,3 — 1Institute for Theoretical Physics, University of Cologne, Germany — 2School of Physics, University College Dublin, Belfield, Dublin 4, Ireland — 3Centre for Quantum Engineering, Science and Technology, University College Dublin, Dublin 4, Ireland
Recent progress in the synthesis of transition metal compounds which are potential cluster Mott insulators provides an opportunity to study these materials more closely. In this work, we use exact diagonalization techniques to study the series of 12L hexagonal perovskites Ba4NbM3O12 and consider different fillings of 3d to 5d transition-metal M ions. These perovskites consist of linear face-sharing M3O12 trimer clusters, and can be best described as lying between the localized-electron picture and molecular orbital picture. We find that the local effective degrees of freedom and other ground-state properties can be shown to be due to an interplay between strong correlations and hopping within the clusters. In addition, we also perform an exhaustive study of all possible fillings on these trimer clusters. Our results show, for example, that there can exist ground state degeneracies that are due to cluster or orbital point group symmetries, in parameter regimes where we might conventionally expect to see a unique ground state. We use our study to hence propose ground state properties and phase diagrams for materials that are likely to be synthesized in the future.
Keywords: Mott Insulators; Extended Hubbard Model; Multi-orbital physics; Molecular Magnets; cluster Mott insulators