{"id":1908,"date":"2015-07-05T21:36:41","date_gmt":"2015-07-06T04:36:41","guid":{"rendered":"http:\/\/physikon.net\/?p=1908"},"modified":"2022-06-22T09:51:10","modified_gmt":"2022-06-22T16:51:10","slug":"1908","status":"publish","type":"post","link":"http:\/\/physikon.net\/?p=1908","title":{"rendered":"High-T<sub>c<\/sub> Superconductivity in Ultra-thin Crystals: Implications for microscopic theory"},"content":{"rendered":"<p><!--more--><\/p>\n<hr \/>\n<p style=\"text-align: justify;\"><strong>High-<em>T<\/em><sub>C<\/sub>\u00a0Superconductivity in Ultra-thin Crystals: Implications for microscopic theory<\/strong>, D. R. Harshman and A. T. Fiory\u00a0[<a href=\"https:\/\/doi.org\/10.48550\/arXiv.1202.0324\">arXiv<\/a>]\n<p style=\"text-align: justify;\">High transition temperature (high-<em>T<\/em><sub>C<\/sub>) superconductivity is associated with layered crystal structures. This work considers superconductivity in ultra-thin crystals (of thickness equal to the transverse structural periodicity distance <em>d<\/em> for one formula unit) of thirty-two cuprate, ruthenate, rutheno-cuprate, iron pnictide, organic, and transuranic compounds, wherein intrinsic optimal (highest) transition temperatures <em>T<\/em><sub>C0<\/sub> (10 &#8211; 150 K) are assumed. Sheet transition temperatures <em>T<\/em><sub>CS<\/sub> = \u03b1 <em>T<\/em><sub>C0<\/sub>, where \u03b1 &lt; 1, are determined from Kosterlitz-Thouless (KT) theory of phase transitions in two-dimensional superconductors. Calculation of a involves superconducting sheet carrier densities N<sub>S<\/sub> derived theoretically from crystal structure, ionic valences, and known doping, a two-fluid model for the temperature dependence of the superconducting magnetic penetration depth, and experimental data on KT transitions; a is on average 0.83 (varying with standard deviation 0.11). Experiments on thin crystal structures approaching thickness d are shown to be consistent with calculations of <em>T<\/em><sub>C0<\/sub> from microscopic superconductivity theory and with <em>T<\/em><sub>CS<\/sub> from KT theory, where the presence of disorder is also taken into account; careful analyses of these thin film studies indicate a minimum thickness <em>d<\/em><sub>F<\/sub> \u2248 <em>d<\/em> for superconductivity.<\/p>\n<p style=\"text-align: justify;\">\n<table id=\"tablepress-13\" class=\"tablepress tablepress-id-13\">\n<tbody class=\"row-hover\">\n<tr class=\"row-1\">\n\t<td class=\"column-1\"><a href=\"http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/EMR_Figure4.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/EMR_Figure4-300x270.jpg\" alt=\"EMR_Figure4\" width=\"300\" height=\"270\" class=\"alignright size-medium wp-image-1384\" srcset=\"http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/EMR_Figure4-300x270.jpg 300w, http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/EMR_Figure4-1024x920.jpg 1024w, http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/EMR_Figure4-167x150.jpg 167w, http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/EMR_Figure4-150x135.jpg 150w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><br \/>\n<p align=\"justify\">The transition temperature <em>T<\/em><sub>C<\/sub> and k<sub>F<\/sub>\u2113 (inset), both plotted as a function of <em>d<\/em><sub>F<\/sub>\/<em>d<\/em> for thin-film Bi<sub>2<\/sub>Sr<sub>2<\/sub>CaCu<sub>2<\/sub>O<sub>8+&delta;<\/sub> samples; The data denoted as \u201cA\u201d (blue squares) correspond to Saito and Kaise (1998) and \u201cB\u201d (red circles) are from Sugimoto et al. (1991).  The solid curve is the theoretical calculation of <em>T<\/em><sub>CS<\/sub> versus <em>d<\/em><sub>F<\/sub>\/<em>d<\/em> with <em>T<\/em><sub>C0<\/sub> = 89 K; the star corresponds to <em>d<\/em><sub>F<\/sub>\/<em>d<\/em> = 1.<\/p><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-13 from cache -->\n<p style=\"text-align: justify;\">D. R. Harshman and A. T. Fiory, <a href=\"https:\/\/doi.org\/10.1680\/emr.11.00001\">Emerging Materials Research <strong>1<\/strong>, 4 (2012)<\/a>.<\/p>\n<hr \/>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":1384,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,8],"tags":[],"class_list":["post-1908","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-high-tc-superconductivity","category-high-tc-theory"],"_links":{"self":[{"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/1908","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1908"}],"version-history":[{"count":17,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/1908\/revisions"}],"predecessor-version":[{"id":7705,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/1908\/revisions\/7705"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/media\/1384"}],"wp:attachment":[{"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1908"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}