Spin disorder competing with positional symmetry breaking governs the metal-insulator behavior in oxide paramagnets

Abstract:Numerous transition-metal oxides have low-temperature, long-range-ordered antiferromagnetic (AFM) states that are generally insulating, and high-temperature, disordered paramagnetic (PM) phases. The latter can be either insulating (predicted here for NaFeO3), or metallic (predicted here and previously observed in NaOsO3). Similar distinctions have been traditionally affected in strongly correlated models by the value used for Coulomb repulsion U. Here we show an alternative, strong-correlation-free (U=0) view suggesting that the distinction between insulating and metallic PM phases is governed by the competition between local magnetic moment disorder and the polymorphous distribution of off-center atomic displacements. Such parameter-free, energy-lowering symmetry breaking density functional calculations provide a framework for understanding metal-insulator behaviors across different quantum materials in terms of measurable local structural and magnetic parameters.

Computational Physics (physics.comp-ph); Materials Science (cond-mat.mtrl-sci); Quantum Physics (quant-ph)

arXiv:2606.14624 [physics.comp-ph]

(or arXiv:2606.14624v2 [physics.comp-ph] for this version)

https://doi.org/10.48550/arXiv.2606.14624 Focus to learn more arXiv-issued DOI via DataCite

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