Damping of spinful excitons in LaCoO.sub.3./sub. by thermal fluctuations: theory and experiment

0534732 - FZÚ 2021 RIV US eng J - Journal Article
Hariki, A. - Wang, R-P. - Sotnikov, A. - Tomiyasu, K. - Betto, D. - Brookes, N.B. - Uemura, Y. - Ghiasi, M. - De Groot, F.M.F. - Kuneš, Jan
Damping of spinful excitons in LaCoO₃ by thermal fluctuations: theory and experiment.
Physical Review B. Roč. 101, č. 24 (2020), s. 1-6, č. článku 245162. ISSN 2469-9950. E-ISSN 2469-9969
EU Projects: European Commission(XE) 646807 - EXMAG
Institutional support: RVO:68378271
Keywords : X-ray-absorption * electronic-structure * transition * state * limit
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4.036, year: 2020
Method of publishing: Limited access
https://doi.org/10.1103/PhysRevB.101.245162

We present Co L3-edge resonant inelastic x-ray scattering (RIXS) of bulk LaCoO3 across the thermally induced spin-state crossover around 100 K. Owing to a high energy resolution of 25 meV, we observe unambiguously the dispersion of the intermediate-spin (IS) excitations in the low-temperature regime. Approaching the intermediate temperature regime, the IS excitations are damped and the bandwidth is reduced. The observed behavior can be well described by a model of mobile IS excitons with strong attractive interaction, which we solve by using dynamical mean-field theory for hard-core bosons. Our results provide a detailed mechanism of how high-spin and IS excitations interact to establish the physical properties of cobaltite perovskites.

Permanent Link: http://hdl.handle.net/11104/0312911