{"id":1869,"date":"2015-07-05T17:10:09","date_gmt":"2015-07-06T00:10:09","guid":{"rendered":"http:\/\/physikon.net\/?p=1869"},"modified":"2022-06-22T09:53:54","modified_gmt":"2022-06-22T16:53:54","slug":"1869","status":"publish","type":"post","link":"http:\/\/physikon.net\/?p=1869","title":{"rendered":"Fluxon Pinning in the Nodeless Pairing State of Superconducting YBa<sub>2<\/sub>Cu<sub>3<\/sub>O<sub>7<\/sub>"},"content":{"rendered":"<p><!--more--><\/p>\n<hr \/>\n<p style=\"text-align: justify;\"><strong>Fluxon Pinning in the Nodeless Pairing State of Superconducting YBa<sub>2<\/sub>Cu<sub>3<\/sub>O<sub>7<\/sub><\/strong>, A. T. Fiory, Dale R. Harshman, J. Jung, I.-Y. Isaac, W. J. Kossler, X. Wan, A. J. Greer, D. R. Noakes, C. E. Stronach, E. Koster and John D. Dow [<a href=\"http:\/\/www3.nd.edu\/~dharshma\/Documents\/TEM_Talk.pdf\" target=\"_blank\" rel=\"noopener\">slides<\/a>]\n<p style=\"text-align: justify;\">Positive-muon spin rotation (\u03bc<sup>+<\/sup>SR) spectroscopy and magnetic moment measurements were used to probe fluxon (or vortex) formation in the superconducting mixed state of a high-purity YBa<sub>2<\/sub>Cu<sub>3<\/sub>O<sub>7<\/sub> crystal.\u00a0 Random potentials caused by crystal-lattice defects pin fluxons.\u00a0 A fluxon lattice forms in an external magnetic field, and changes of thermal activation lead to fluxon pinning and depinning. The root second moment of the local magnetic field distribution (\u03c3) determined by \u03bc<sup>+<\/sup>SR contains information on the magnetic penetration depth and the pinning. Fluxon pinning leads to temperature-dependent transverse displacements of the fluxons that decrease \u03c3 and also fluctuations in the separation between fluxons that tend to increase \u03c3.\u00a0 By accounting for the field-dependent and temperature-activated fluxon disorder, it is found that the experimental results for the penetration depth are consistent with a superconducting order parameter of a strong-coupling two-fluid model, confirming that the superconductivity is nodeless with <em>s<\/em>-wave superconducting pairing.\u00a0 Quantitative results for fluxon displacements are discussed within the context of the fluxon field-temperature phase diagram.<\/p>\n\n<table id=\"tablepress-7\" class=\"tablepress tablepress-id-7\">\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\/sigma_T_fiory.jpg\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/sigma_T_fiory-300x267.jpg\" alt=\"sigma_T_fiory\" width=\"300\" height=\"267\" class=\"alignleft size-medium wp-image-1299\" srcset=\"http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/sigma_T_fiory-300x267.jpg 300w, http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/sigma_T_fiory-169x150.jpg 169w, http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/sigma_T_fiory-150x134.jpg 150w, http:\/\/physikon.net\/wp-content\/uploads\/2015\/05\/sigma_T_fiory.jpg 573w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><br \/>\n<p align=\"justify\">Root second moment of internal magnetic field distribution in YBa<sub>2<\/sub>Cu<sub>3<\/sub>O<sub>7<\/sub> crystal cooled in fields of H 0.05, 1. 3 and 6 T. Curves are fits obtained with a two-fluid model of s-wave pairing and model of fluxon pinning and depinning.<p><br \/>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<!-- #tablepress-7 from cache -->\n<p style=\"text-align: justify;\">A. T. Fiory, Dale R. Harshman, J. Jung, I.-Y. Isaac, W. J. Kossler, X. Wan, A. J. Greer, D. R. Noakes, C. E. Stronach, E. Koster and John D. Dow, Invited Paper, in <i>Proceedings of the 133<sup>rd<\/sup> Annual Meeting of the Minerals, Metals, Materials Society (TMS)<\/i>, Charlotte, North Carolina, 14-18 March 2004, <a href=\"https:\/\/doi.org\/10.1007\/s11664-005-0054-0\">Journal of Electronic Materials <strong>34<\/strong>, 474 (2005)<\/a>.<\/p>\n<hr \/>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":1299,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,9,10],"tags":[],"class_list":["post-1869","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fluxon-pinning-and-dynamics","category-high-tc-superconductivity","category-pairing-state-symmetry"],"_links":{"self":[{"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/1869","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=1869"}],"version-history":[{"count":28,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/1869\/revisions"}],"predecessor-version":[{"id":7711,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/posts\/1869\/revisions\/7711"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=\/wp\/v2\/media\/1299"}],"wp:attachment":[{"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1869"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/physikon.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}