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arXiv · 1911.07545

High-resolution resonant inelastic x-ray scattering study of the electron-phonon coupling in honeycomb $\alpha$-Li$_2$IrO$_3$

J. G. Vale·C. D. Dashwood·E. Paris·L. S. I. Veiga·M. Garcia-Fernandez·A. Nag·A. Walters·K. J. Zhou·I. -M. Pietsch·A. Jesche·P. Gegenwart·R. Coldea·T. Schmitt·D. F. McMorrow
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Abstract

The excitations in honeycomb $\alpha$-Li$_2$IrO$_3$ have been investigated with high-resolution resonant inelastic x-ray scattering (RIXS) at the O K edge. The low-energy response is dominated by a fully resolved ladder of excitations, which we interpret as being due to multi-phonon processes in the presence of strong electron-phonon coupling (EPC). At higher energies, the orbital excitations are shown to be dressed by phonons. The high quality of the data permits a quantitative test of the analytical model for the RIXS cross-section, which has been proposed to describe EPC in transition metal oxides (TMOs). We find that the magnitude of the EPC is comparable to that found for a range of 3d TMOs. This indicates that EPC may be of equal importance in determining the phenomenology displayed by corresponding 5d based systems.

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J. G. Vale, C. D. Dashwood, E. Paris, L. S. I. Veiga, M. Garcia-Fernandez, A. Nag, A. Walters, K. J. Zhou, I. -M. Pietsch, A. Jesche, P. Gegenwart, R. Coldea, T. Schmitt, D. F. McMorrow. 2019-11-18. High-resolution resonant inelastic x-ray scattering study of the electron-phonon coupling in honeycomb $\alpha$-Li$_2$IrO$_3$. https://doi.org/10.1103/physrevb.100.224303

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