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arXiv · 2408.15540

Identifying the phases of Kane-Mele Hubbard Hamiltonian in momentum space: A many-body configuration interaction study

Ranadeep Roy·Sasmita Mohakud·Katsunori Wakabayashi·Sudipta Dutta
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Abstract

We investigate the magnetic and conduction properties of Kane-Mele Hubbard model in quasi one-dimensional honeycomb ribbon systems at half-filling by varying the strength of both spin-orbit interaction and on-site Coulomb correlation term. We use the numerical many-body configuration interaction (CI) method to investigate the dispersions of charge and spin gaps along with the momentum resolved spin-density profile over the full Brillouin zone. While the spin sector retains its topological nature at all values of spin-orbit coupling and Hubbard term, we report a new signature of the topological phase transition in the charge sector. This phase transition from a topological band insulating phase to a antiferromagnetically ordered Mott insulating phase is characterized by a shift of the many-body charge gap minima from Brillouin zone boundary to Dirac point. Our results provide a better understanding of the shifting of the gap-closing point in the momentum space which was reported in an earlier mean-field study of the same model and suggests an alternative numerical route to detect topological phase transition in strongly-correlated systems in terms of their momentum space behaviors.

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Ranadeep Roy, Sasmita Mohakud, Katsunori Wakabayashi, Sudipta Dutta. 2024-08-28. Identifying the phases of Kane-Mele Hubbard Hamiltonian in momentum space: A many-body configuration interaction study. https://arxiv.org/abs/2408.15540

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