{"paper":{"title":"Ab initio calculation of low-energy collective charge-density excitations in MgB2","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.supr-con","authors_text":"A. Balassis, E. V. Chulkov, P. M. Echenique, V. M. Silkin","submitted_at":"2008-05-11T20:06:42Z","abstract_excerpt":"We present {\\it ab-initio} time-dependent density-functional theory calculation results for low-energy collective electron excitations in $\\textrm{MgB}_2$. The existence of a long-lived collective excitation corresponding to coherent charge density fluctuations between the boron $\\sigma$- and $\\pi$- bands ($\\sigma\\pi$ mode) is demonstrated. This mode has a sine-like oscillating dispersion for energies below 0.5 eV. At even lower energy we find another collective mode ($\\sigma\\sigma$ mode). We show the strong impact of local-field effects on dielectric functions in MgB$_2$. These effects accoun"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0805.1558","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"}