{"paper":{"title":"Highly anisotropic superconducting gap in underdoped Ba$_{1-x}$K$_x$Fe$_2$As$_2$","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.supr-con","authors_text":"Bing Shen, Hai-Hu Wen, H. Kim, M. A. Tanatar, R. Prozorov","submitted_at":"2011-05-11T17:51:33Z","abstract_excerpt":"The in-plane London penetration depth, $\\Delta\\lambda(T)$, was measured using a tunnel diode resonator in single crystals of Ba$_{1-x}$K$_x$Fe$_2$As$_2$ for five doping levels $x$ ranging from underdoped, $T_c$=11 K ($x$=0.17), to optimally doped, $T_c=$38 K ($x_\\textmd{\\scriptsize opt}$= 0.35). In the optimally doped samples, $\\Delta\\lambda(T)$ shows exponential saturation in $T \\to 0$ limit suggesting a fully gapped superconductivity. The lowest-$T_c$ samples show much stronger non-exponential variation of $\\Delta\\lambda(T)$. Fitting the data to a power-law, $\\Delta\\lambda(T)= AT^n$, reveals"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1105.2265","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"}