{"paper":{"title":"Lattice dynamics, crystal-field excitations and quadrupolar fluctuations of YbRu$_2$Ge$_2$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.str-el","authors_text":"E. W. Rosenberg, G. Blumberg, I. R. Fisher, Mai Ye","submitted_at":"2019-02-07T21:59:11Z","abstract_excerpt":"We report Raman-scattering results of YbRu$_2$Ge$_2$ single crystals to explore the phononic and crystal-field (CF) excitations. This heavy-fermion metal is suggested to enter a ferroquadrupolar (FQ) phase below T$_0$=10 K. The tetragonal CF potential splits the Yb$^{3+}$ $^2F_{7/2}$ ground multiplet into two $\\Gamma_6$ and two $\\Gamma_7$ Kramers doublets. We establish the following CF level scheme of the ground multiplet: a $\\Gamma_6$ ground state, with the two $\\Gamma_7$ states at 2 cm$^{-1}$, 95 cm$^{-1}$ and the other $\\Gamma_6$ state at 239 cm$^{-1}$. The $\\sim$2 cm$^{-1}$ separation betw"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1902.02863","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}