Spin-0 Mott insulator to metal to spin-1 Mott insulator transition in the single-orbital Hubbard model on the decorated honeycomb lattice Article Swipe
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· 2021
· Open Access
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· DOI: https://doi.org/10.1103/physrevb.104.075104
· OA: W3142090136
We study the interplay of strong electron correlations and intra-triangle\nspin exchange at two-thirds filling of the single-orbital Hubbard model on the\ndecorated honeycomb lattice using rotationally invariant slave bosons. We find\nthat the spin exchange tunes between a spin-$1$ Mott insulator, a metal, and a\nspin-$0$ Mott insulator when the exchange is antiferromagnetic. The Mott\ninsulators occur from effective intra-triangle multi-orbital interactions and\nare adiabatically connected to the ground state of an isolated triangle. An\nantiferromagnetic spin exchange, as determined by the Goodenough-Kanamori\nrules, may occur in coordination polymers from kinetic exchange via the\nligands. We characterize the magnetism in the regime where spin-triplets\ndominate. For small $U$ a spin-$1$ Slater insulator occurs with\nantiferromagnetic order between triangles. Magnetism in the spin-$1$ Mott\ninsulator is described by a spin-$1$ Heisenberg model on a honeycomb lattice,\nwhose ground state is N\\'{e}el ordered.\n
