We employ polarization-resolved Raman scattering spectroscopy to study ferroquadrupolar (FQ) fluctuations and crystal-field (CF) excitations in the YbRu2Ge2 heavy-fermion metal with FQ transition at TQ=10K. We demonstrate that the electronic static Raman susceptibilities in quadrupolar symmetry channels exhibit nearly Curie law behavior and that the electron-lattice coupling is essential for the FQ transition at TQ. We establish the CF level scheme of the Yb3+ ground state F7/22 multiplet. We study the lattice dynamics and demonstrate coupling between CF transitions and phonon modes.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics