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arXiv · 1803.06945

Spin-orbital-lattice entangled states in cubic $d^1$ double perovskites

Naoya Iwahara·Veacheslav Vieru·Liviu F. Chibotaru
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Abstract

Interplay of spin-orbit coupling and vibronic coupling on heavy $d^1$ site of cubic double perovskites is investigated by ab initio calculations. The stabilization energy of spin-orbital-lattice entangled states is found comparable to or larger than the exchange interactions, suggesting the presence of Jahn-Teller dynamics in the systems. In Ba$_2$YMoO$_6$, the pseudo JT coupling enhances the mixing of the ground and excited spin-orbit multiplet states, which results in strong temperature dependence of effective magnetic moments. The entanglement of the spin and lattice degrees of freedom induces a strong magneto-elastic response. This multiferroic effect is at the origin of the recently reported breaking of local point symmetry accompanying the development of magnetic ordering in Ba$_2$NaOsO$_6$.

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Naoya Iwahara, Veacheslav Vieru, Liviu F. Chibotaru. 2018-08-03. Spin-orbital-lattice entangled states in cubic $d^1$ double perovskites. https://doi.org/10.1103/physrevb.98.075138

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