Vibronic excitations in resonant inelastic x-ray scattering spectra of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi mathvariant="normal">K</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>RuCl</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>
Naoya Iwahara, Shouta Shikano
Abstract
We present the fingerprints of the dynamic Jahn-Teller effect in resonant inelastic x-ray scattering (RIXS) spectra of ${\mathrm{K}}_{2}{\mathrm{RuCl}}_{6}$. We determined the dynamic Jahn-Teller model Hamiltonian of an embedded ${\mathrm{Ru}}^{4+}$ ion using post-Hartree-Fock methods, and derived the vibronic states by numerically diagonalizing the Hamiltonian. With the obtained vibronic states, we reproduced the RIXS spectra. The shape and the temperature dependence of the RIXS spectrum agree well with the experimental data. We found that some peaks emerge due to the dynamic Jahn-Teller effect rather than the crystal-field splitting. Our paper indicates the significance of the Jahn-Teller coupling to adequately interpret RIXS spectra.