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arXiv · 2009.11773

Evolution of Spin-Orbital Entanglement with Increasing Ising Spin-Orbit Coupling

Dorota Gotfryd·Ekaterina Paerschke·Krzysztof Wohlfeld·Andrzej M. Oles
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Abstract

Several realistic spin-orbital models for transition metal oxides go beyond the classical expectations and could be understood only by employing the quantum entanglement. Experiments on these materials confirm that spin-orbital entanglement has measurable consequences. Here, we capture the essential features of spin-orbital entanglement in complex quantum matter utilizing 1D spin-orbital model which accommodates SU(2)xSU(2) symmetric Kugel-Khomskii superexchange as well as the Ising on-site spin-orbit coupling. Building on the results obtained for full and effective models in the regime of strong spin-orbit coupling, we address the question whether the entanglement found on superexchange bonds always increases when the Ising spin-orbit coupling is added. We show that (i) quantum entanglement is amplified by strong spin-orbit coupling and, surprisingly, (ii) almost classical disentangled states are possible. We complete the latter case by analyzing how the entanglement existing for intermediate values of spin-orbit coupling can disappear for higher values of this coupling.

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Dorota Gotfryd, Ekaterina Paerschke, Krzysztof Wohlfeld, Andrzej M. Oles. 2020-09-24. Evolution of Spin-Orbital Entanglement with Increasing Ising Spin-Orbit Coupling. https://doi.org/10.3390/condmat5030053

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