{"paper":{"title":"Observation of the Presuperfluid Regime in a Two-Dimensional Bose Gas","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.quant-gas","authors_text":"D. Lobser, E. A. Cornell, G. Lamporesi, L. Xia, S. Tung","submitted_at":"2010-09-13T18:56:19Z","abstract_excerpt":"In complementary images of coordinate-space and momentum-space density in a trapped 2D Bose gas, we observe the emergence of pre-superfluid behavior. As phase-space density $\\rho$ increases toward degenerate values, we observe a gradual divergence of the compressibility $\\kappa$ from the value predicted by a bare-atom model, $\\kappa_{ba}$. $\\kappa/\\kappa_{ba}$ grows to 1.7 before $\\rho$ reaches the value for which we observe the sudden emergence of a spike at $p=0$ in momentum space. Momentum-space images are acquired by means of a 2D focusing technique. Our data represent the first observatio"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1009.2475","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"}