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arXiv · 1708.04417

Coulomb correlations intertwined with spin and orbital excitations in LaCoO$_3$

K. Tomiyasu·J. Okamoto·H. Y. Huang·Z. Y. Chen·E. P. Sinaga·W. B. Wu·Y. Y. Chu·A. Singh·R. -P. Wang·F. M. F. de Groot·A. Chainani·S. Ishihara·C. T. Chen·D. J. Huang
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Abstract

We carried out temperature-dependent (20 - 550 K) measurements of resonant inelastic X-ray scattering on LaCoO$_3$ to investigate the evolution of its electronic structure across the spin-state crossover. In combination with charge-transfer multiplet calculations, we accurately quantized the renormalized crystal-field excitation energies and spin-state populations. We show that the screening of the on-site Coulomb interaction of 3d electrons is orbital selective and coupled to the spin-state crossover in LaCoO$_3$. The results establish that the gradual spin-state crossover is associated with a relative change of Coulomb energy versus bandwidth, leading to a Mott-type insulator-to-metal transition.

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K. Tomiyasu, J. Okamoto, H. Y. Huang, Z. Y. Chen, E. P. Sinaga, W. B. Wu, Y. Y. Chu, A. Singh, R. -P. Wang, F. M. F. de Groot, A. Chainani, S. Ishihara, C. T. Chen, D. J. Huang. 2017-08-15. Coulomb correlations intertwined with spin and orbital excitations in LaCoO$_3$. https://doi.org/10.1103/physrevlett.119.196402

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