{"paper":{"title":"Doping - dependent anisotropic superconducting gap in Na$_{1-\\delta}$(Fe$_{1-x}$Co$_x$)As","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cond-mat.supr-con","authors_text":"C. L. Zhang, G. Tan, H. Kim, K. Cho, M. A. Tanatar, N. Spyrison, P. Dai, R. Prozorov","submitted_at":"2012-01-13T22:09:11Z","abstract_excerpt":"The London penetration depth was measured in single crystals of self-doped Na$_{1-\\delta}$FeAs (from under - to optimal - doping, $T_c$ from 14 to 27 K) and electron-doped Na(Fe$_{1-x}$Co$_{x}$)As with $x$ ranging from undoped, $x=0$ to overdoped $x= 0.1$. In all samples, the low - temperature variation of the penetration depth exhibits a power-law dependence, $\\Delta \\lambda (T) = AT^n$, with the exponent that varies in a dome - like fashion from $n \\sim 1.1$ in the underdoped, reaching a maximum of $n \\sim 1.9$ in the optimally doped and decreasing again to $n \\sim 1.3$ on the overdoped side"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1201.2966","kind":"arxiv","version":3},"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"}