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

Condensed Matter

Ekaterina Pärschke¹  Dorota Gotfryd²  Krzysztof Wohlfeld²  AndrzejM. Oleś³ 

[1] Institute of Science and Technology Austria, Am Campus 1, A-3400 Klosterneuburg, Austria;Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, PL-02093 Warsaw, Poland;Institute of Theoretical Physics, Jagiellonian University, Profesora Stanisława ojasiewicza 11, PL-30348 Krakow, Poland;

关键词: spin-orbital entanglement;    spin-orbit coupling;    product state;    Mott insulator;    antiferromagnet;    ferromagnet;   

DOI  :  10.3390/condmat5030053

来源: DOAJ

【 摘 要 】

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)⊗SU(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.

【 授权许可】

Unknown