{"paper":{"title":"Observation of low energy dispersive modes in un- derdoped (La, Nd) 2--x Sr x CuO 4","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cond-mat.supr-con"],"primary_cat":"cond-mat.str-el","authors_text":"Abhay Shukla (IMPMC), Alessandra Lanzara, Alexei Bossak (ESRF), Claudia Decorse (ICMMO), Daniel Lamago (LLB - UMR 12), Jeff Graf, John-Paul Castellan (LLB - UMR 12), Matteo D 'Astuto (IMPMC), Michael Krisch (ESRF), Paola Giura (IMPMC), Patrick Berthet (ICMMO), Sang-Wook Cheong (RUTGERS), Sylvain Denis (ICMMO)","submitted_at":"2015-02-13T14:27:47Z","abstract_excerpt":"We find excitations lower in energy than known phonon modes in underdoped La$\\_{2-x}$Sr$\\_x$CuO$\\_{4+\\delta}$ (x=0.08), with both inelastic X-Ray scattering (IXS) and inelastic neutron scattering (INS). A non dispersive excitation at 9 meV is identified and is also seen by INS in (La,Nd)$\\_{2-x}$Sr$\\_x$CuO$\\_{4+\\delta}$, with 40$\\%$ Nd substitution. INS also identifies a still lower energy dispersive mode at low q in the Nd free sample. These modes are clearly distinct from the longitudinal acoustic phonon and correspond in energy to the Zone Centre modes measured by optical spectroscopy and a"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1502.04003","kind":"arxiv","version":1},"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"}