{"id":2450,"date":"2025-05-21T17:20:11","date_gmt":"2025-05-21T15:20:11","guid":{"rendered":"https:\/\/webs.uab.cat\/giq\/?post_type=seminar&#038;p=2450"},"modified":"2025-05-21T17:20:12","modified_gmt":"2025-05-21T15:20:12","slug":"many-body-entanglement-quantification-with-collective-measurements","status":"publish","type":"seminar","link":"https:\/\/webs.uab.cat\/giq\/seminar\/many-body-entanglement-quantification-with-collective-measurements\/","title":{"rendered":"Many-body entanglement quantification with collective measurements"},"content":{"rendered":"\n<p><em>I will present some recent results on entanglement detection and quantification with collective measurements in many-body ensembles. First I will give an introduction into entanglement and the idea of &#8216;spin squeezing&#8217;, which was introduced in the context of metrology, and explain the relation between the two concepts. I will show how the original spin squeezing approach can be generalized in several respects and how it allows to quantify multipartite entanglement in different types of experimentally-controlled many-body systems, such as cold atomic clouds or solid-state magnetic materials. These entanglement witnesses are based on variances of collective operators, which can be extracted from simple averaged two-body correlation functions, which is the reason why they find widespread application in many-body systems, where higher-order correlation functions of more complex measurements are generally very challenging. In particular I will present particular examples of criteria that have been recently applied to quantify entanglement in experiments with cold or ultracold atomic gases.In the final part, I will focus on the quantification of entanglement by means of entanglement monotones with similar methods, and I will show the results of applying this method to many-spin systems at equilibrium as well as with experimental data of a spin-squeezed Bose-Einstein condensates of \u223c500 atoms.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>I will present some recent results on entanglement detection and quantification with collective measurements in many-body ensembles. First I will give an introduction into entanglement and the idea of &#8216;spin squeezing&#8217;, which was introduced in the context of metrology, and explain the relation between the two concepts. I will show how the original spin squeezing [&hellip;]<\/p>\n","protected":false},"author":2605,"featured_media":0,"template":"","class_list":["post-2450","seminar","type-seminar","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/seminar\/2450","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/seminar"}],"about":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/types\/seminar"}],"author":[{"embeddable":true,"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/users\/2605"}],"wp:attachment":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/media?parent=2450"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}