{"id":73673,"date":"2025-05-22T14:47:01","date_gmt":"2025-05-22T12:47:01","guid":{"rendered":"https:\/\/www.iemn.fr\/?p=73673"},"modified":"2025-06-04T14:14:57","modified_gmt":"2025-06-04T12:14:57","slug":"seminaire-pierre-deymier-acoustic-geometric-phase-computing-sensing-and-engineering-2-juin-2-2","status":"publish","type":"post","link":"https:\/\/www.iemn.fr\/en\/a-la-une\/seminaire-pierre-deymier-acoustic-geometric-phase-computing-sensing-and-engineering-2-juin-2-2.html","title":{"rendered":"S\u00e9minaire : Georges Bouzerar &lsquo;Generating long-distance magnetic couplings with flat bands&rsquo; &#8211; 13 juin"},"content":{"rendered":"<div  class='flex_column av-vq9ow6-4ea65ffd1d4e0be7a5230f1077847b71 av_one_full  avia-builder-el-0  avia-builder-el-no-sibling  first flex_column_div'     ><section  class='av_textblock_section av-mazchq0s-aa5f04d93e6c3bb80342cae114145ef6'   itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/BlogPosting\" itemprop=\"blogPost\" ><div class='avia_textblock'  itemprop=\"text\" ><h4>Generating long-distance magnetic couplings with flat bands<\/h4>\n<p><strong><span style=\"color: #800000;\">\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-13ewzjw-10-2ccad9ba8c63aebd0958467334f1a6d9\">\n.av_font_icon.av-13ewzjw-10-2ccad9ba8c63aebd0958467334f1a6d9{\ncolor:#f16728;\nborder-color:#f16728;\n}\n.av_font_icon.av-13ewzjw-10-2ccad9ba8c63aebd0958467334f1a6d9 .av-icon-char{\nfont-size:20px;\nline-height:20px;\n}\n<\/style>\n<span  class='av_font_icon av-13ewzjw-10-2ccad9ba8c63aebd0958467334f1a6d9 avia_animate_when_visible av-icon-style- avia-icon-pos-left avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue885' data-av_iconfont='entypo-fontello' ><\/span><\/span><\/span><span style=\"color: #f16728;\">Par Dr. Georges Bouzerar &#8211; <\/span><\/strong>Institut N\u00e9el<\/p>\n<p><a href=\"https:\/\/scholar.google.com\/citations?hl=fr&amp;user=Z6MgV9kAAAAJ&amp;view_op=list_works&amp;sortby=pubdate\" target=\"_blank\" rel=\"noopener\"><strong><span style=\"color: #800000;\">\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-13ewzjw-10-1-b4a54ade627b32af46f36cd660d59f3b\">\n.av_font_icon.av-13ewzjw-10-1-b4a54ade627b32af46f36cd660d59f3b{\ncolor:#f16728;\nborder-color:#f16728;\n}\n.av_font_icon.av-13ewzjw-10-1-b4a54ade627b32af46f36cd660d59f3b .av-icon-char{\nfont-size:20px;\nline-height:20px;\n}\n<\/style>\n<span  class='av_font_icon av-13ewzjw-10-1-b4a54ade627b32af46f36cd660d59f3b avia_animate_when_visible av-icon-style- avia-icon-pos-center avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue803' data-av_iconfont='entypo-fontello' ><\/span><\/span><\/span><\/strong><\/a><\/p>\n<hr \/>\n<p><strong><span style=\"color: #800000;\">\n<style type=\"text\/css\" data-created_by=\"avia_inline_auto\" id=\"style-css-av-13ewzjw-10-2-17e55b3dba3799c400f8b429ee4bccc2\">\n.av_font_icon.av-13ewzjw-10-2-17e55b3dba3799c400f8b429ee4bccc2{\ncolor:#f16728;\nborder-color:#f16728;\n}\n.av_font_icon.av-13ewzjw-10-2-17e55b3dba3799c400f8b429ee4bccc2 .av-icon-char{\nfont-size:20px;\nline-height:20px;\n}\n<\/style>\n<span  class='av_font_icon av-13ewzjw-10-2-17e55b3dba3799c400f8b429ee4bccc2 avia_animate_when_visible av-icon-style- avia-icon-pos-left avia-icon-animate'><span class='av-icon-char' aria-hidden='true' data-av_icon='\ue84e' data-av_iconfont='entypo-fontello' ><\/span><\/span><\/span><span style=\"color: #f16728;\">Abstract:<\/span><\/strong> \u00ab\u00a0It is well known and intuitively understandable that magnetic couplings in materials decrease extremely rapidly as the distance between localized spins increases. In this study, we reveal an unusual and unexpected phenomenon that completely challenges and contradicts this well-established fact. It is possible in flat-band (FB) materials to significantly amplify (orders of magnitude) the magnetic couplings between widely separated spins. We show that the underlying mechanism that enables the boost of the magnetic couplings is connected to a geometric characteristic of FB eigenstates known as the quantum metric (QM). The QM provides a measure of the square of the typical spread of FB eigenstates. It plays an essential role in explaining the origin of the superconducting phase in twisted bilayer graphene in the vicinity of magic angles. We believe that our findings could be of great interest in the search for high temperature 2D ferromagnetic systems and for long-distance quantum communication that requires lossless transfer of a quantum state between distant quantum registers.\u00a0\u00bb<\/p>\n<\/div><\/section><\/div>","protected":false},"excerpt":{"rendered":"","protected":false},"author":2,"featured_media":73854,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-73673","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-a-la-une"],"_links":{"self":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/73673","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/comments?post=73673"}],"version-history":[{"count":7,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/73673\/revisions"}],"predecessor-version":[{"id":73675,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/posts\/73673\/revisions\/73675"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media\/73854"}],"wp:attachment":[{"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/media?parent=73673"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/categories?post=73673"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.iemn.fr\/en\/wp-json\/wp\/v2\/tags?post=73673"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}