J. J. Lee, B. Moritz, W. S. Lee, M. Yi, C. J. Jia, A. P. Sorini, K. Kudo, Y. Koike, K. J. Zhou, C. Monney, V. Strocov, L. Patthey, T. Schmitt, T. P. Devereaux, and Z. X. Shen:
Phys. Rev. B 89, 041104(R) (2014), pp. 5;
We identify dd excitations in the quasi-one-dimensional compound Ca2Y2Cu5O10 using resonant inelastic x-ray scattering. By tuning across the Cu L3 edge, we observe abrupt shifts in the dd-peak positions as a function of incident photon energy. This observation demonstrates orbital-specific coupling of the high-energy excited states of the system to the low-energy degrees of freedom. A Franck-Condon treatment of electron-lattice coupling, consistent with other measurements in this compound, reproduces these shifts, explains the Gaussian line shapes, and highlights charge-orbital-lattice renormalization in the high-energy d manifold.
The original publication is available by link DOI: 10.1103/PhysRevB.89.041104