Anomalously strong two-electron one-photon X-ray decay transitions in CO caused by avoided crossing

作者：Couto Rafael C; Guarise Marco^*; Nicolaou Alessandro; Jaouen Nicolas; Chiuzbaian Gheorghe S; Luening Jan; Ekholm Victor; Rubensson Jan Erik; Sathe Conny; Hennies Franz; Kimberg Victor; Guimaraes Freddy F; Agren Hans; Gel'mukhanov Faris; Journel Loic; Simon Marc

来源：Scientific Reports, 2016, 6(1): 20947.

DOI：10.1038/srep20947

The unique opportunity to study and control electron-nuclear quantum dynamics in coupled potentials offered by the resonant inelastic X-ray scattering (RIXS) technique is utilized to unravel an anomalously strong two-electron one-photon transition from core-excited to Rydberg final states in the CO molecule. High-resolution RIXS measurements of CO in the energy region of 12-14 eV are presented and analyzed by means of quantum simulations using the wave packet propagation formalism and ab initio calculations of potential energy curves and transition dipole moments. The very good overall agreement between the experimental results and the theoretical predictions allows an in-depth interpretation of the salient spectral features in terms of Coulomb mixing of "dark" with "bright" final states leading to an effective two-electron one-photon transition. The present work illustrates that the improved spectral resolution of RIXS spectra achievable today may call for more advanced theories than what has been used in the past.

• 出版日期2016-2-10