{"id":8308,"date":"2024-12-25T10:27:13","date_gmt":"2024-12-25T18:27:13","guid":{"rendered":"http:\/\/physikon.net\/?p=8308"},"modified":"2026-02-08T07:51:58","modified_gmt":"2026-02-08T15:51:58","slug":"interfacial-superconductivity-in-cu-cu2o-and-its-effect-on-shielding-ambient-electric-fields","status":"publish","type":"post","link":"http:\/\/physikon.net\/?p=8308","title":{"rendered":"Interfacial Superconductivity in Cu\/Cu<sub>2<\/sub>O and its Effect on Shielding Ambient Electric Fields"},"content":{"rendered":"<p><!--more--><\/p>\n<hr \/>\n<p style=\"text-align: justify;\"><strong>Interfacial Superconductivity in Cu\/Cu<sub>2<\/sub>O and its Effect on Shielding Ambient Electric Fields<\/strong>, Dale R. Harshman and Anthony T. Fiory [<a href=\"https:\/\/arxiv.org\/abs\/2505.02328\">arXiv<\/a>]\n<p style=\"text-align: justify;\">A model is presented for two-dimensional superconductivity at semiconductor-on-metal interfaces mediated by Coulomb interactions between electronically-active interface charges in the semiconductor and screening charges in the metal. The junction considered is native Cu<sub>2<\/sub>O on Cu in which an interfacial double charge layer of areal density <em>n<\/em>, comprising superconducting holes in Cu<sub>2<\/sub>O and mediating electrons in Cu, is induced in proportion to a sub-monolayer of adsorbed <sup>4<\/sup>He atoms. Evidence for superconductivity on copper with prior air exposure is revealed in new analysis of previously published work function data. Based on a theory developed for layered superconductors, the intrinsic transition temperature <em>T<\/em><sub>C<\/sub> = \u03b2 <em>n<\/em><sup>1\/2<\/sup>\/\u03b6 is determined by <em>n<\/em> and transverse distance \u03b6 \u2243 2.0 \u00c5 between the charge layers; \u03b2 = 1.933(6) <em>e<\/em><sup>2<\/sup>\u019b<sub>C<\/sub>\/<em>k<\/em><sub>B<\/sub> = 1247.4(3.7) K-\u00c5<sup>2<\/sup> is a universal constant involving the reduced Compton wavelength of the electron \u019b<sub>C<\/sub>. This model is applied to understanding the shielding of copper work-function patch and gravitational compression electric fields reported in the Witteborn-Fairbank gravitational electron free fall experiment. Interfacial superconductivity with <em>n<\/em> \u2243 1.6 \u00d7 10<sup>12<\/sup> cm<sup>\u22122<\/sup>, <em>T<\/em><sub>C<\/sub> \u2243 7.9 K and Berezinski\u012d-Kosterlitz-Thouless temperature <em>T<\/em><sub>BKT<\/sub> \u2243 4.4 K accounts for the shielding observed at temperature <em>T<\/em> \u2243 4.2 K. Helium desorption and concomitant decreases in <em>n<\/em> and <em>T<\/em><sub>C<\/sub> replicate the temperature transition in ambient electric fields on falling electrons, as observed by Lockhart et al., and the vanishing of superconductivity above <em>T<\/em> \u2243 4.8 K.<\/p>\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"982\" src=\"http:\/\/physikon.net\/wp-content\/uploads\/Figure6-1024x982.jpg\" alt=\"\" class=\"wp-image-8318\" srcset=\"http:\/\/physikon.net\/wp-content\/uploads\/Figure6-1024x982.jpg 1024w, http:\/\/physikon.net\/wp-content\/uploads\/Figure6-300x288.jpg 300w, http:\/\/physikon.net\/wp-content\/uploads\/Figure6-768x736.jpg 768w, http:\/\/physikon.net\/wp-content\/uploads\/Figure6-1536x1473.jpg 1536w, http:\/\/physikon.net\/wp-content\/uploads\/Figure6-2048x1964.jpg 2048w, http:\/\/physikon.net\/wp-content\/uploads\/Figure6-150x144.jpg 150w, http:\/\/physikon.net\/wp-content\/uploads\/Figure6-156x150.jpg 156w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\"><p style=\"text-align: justify;\">Fig. 6. Ambient electric field inside copper tube vs. temperature.  Filled symbols (LWF) denote data from Refs. [34] and [100]; open square symbol (WF) from Ref. [30].  Solid (red), dashed (green), and dotted (blue) curves are obtained with reduced normal-state resistance r<sub>N<\/sub> = 1.0, 0.5, and 1.5, respectively.<\/p> <\/figcaption><\/figure>\n\n\n\n<p>D. R. Harshman and A. T. Fiory, <a href=\"https:\/\/doi.org\/10.1016\/j.physc.2024.1354600\">Physica C: Superconductivity and its Applications <strong>632<\/strong>, 1354600 (2025)<\/a>; <strong>Corrigendum:<\/strong> <a href=\"https:\/\/doi.org\/10.1016\/j.physc.2025.1354752\">Physica C: Superconductivity and its Applications <strong>632<\/strong>, 1354752 (2025<\/a>).<\/p>\n","protected":false},"excerpt":{"rendered":"<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,8,28],"tags":[],"class_list":["post-8308","post","type-post","status-publish","format-standard","hentry","category-high-tc-superconductivity","category-high-tc-theory","category-transition-temperature"],"_links":{"self":[{"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/8308","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=8308"}],"version-history":[{"count":23,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/8308\/revisions"}],"predecessor-version":[{"id":8549,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/8308\/revisions\/8549"}],"wp:attachment":[{"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8308"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8308"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8308"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}