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arXiv · 2304.11154

Transition to the Haldane phase driven by electron-electron correlations

A. Jażdżewska·M. Mierzejewski·M. Środa·A. Nocera·G. Alvarez·E. Dagotto·J. Herbrych
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Abstract

One of the most famous quantum systems with topological properties, the spin $\mathcal{S}=1$ antiferromagnetic Heisenberg chain, is well-known to display exotic $\mathcal{S}=1/2$ edge states. However, this spin model has not been analyzed from the more general perspective of strongly correlated systems varying the electron-electron interaction strength. Here, we report the investigation of the emergence of the Haldane edge in a system of interacting electrons -- the two-orbital Hubbard model -- with increasing repulsion strength $U$ and Hund interaction $J_\mathrm{H}$. We show that interactions not only form the magnetic moments but also form a topologically nontrivial fermionic many-body ground-state with zero-energy edge states. Specifically, upon increasing the strength of the Hubbard repulsion and Hund exchange, we identify a sharp transition point separating topologically trivial and nontrivial ground-states. Surprisingly, such a behaviour appears already at rather small values of the interaction, in a regime where the magnetic moments are barely developed.

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A. Jażdżewska, M. Mierzejewski, M. Środa, A. Nocera, G. Alvarez, E. Dagotto, J. Herbrych. 2023-04-21. Transition to the Haldane phase driven by electron-electron correlations. https://doi.org/10.1038/s41467-023-44135-9

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