{"id":986,"date":"2014-04-28T17:53:35","date_gmt":"2014-04-28T15:53:35","guid":{"rendered":"https:\/\/webs.uab.cat\/giq\/seminar\/linear-vs-non-linear-gaussian-state-discrimination\/"},"modified":"2014-04-28T17:53:35","modified_gmt":"2014-04-28T15:53:35","slug":"linear-vs-non-linear-gaussian-state-discrimination","status":"publish","type":"seminar","link":"https:\/\/webs.uab.cat\/giq\/seminar\/linear-vs-non-linear-gaussian-state-discrimination\/","title":{"rendered":"Linear vs non-linear &#8211; Gaussian state discrimination"},"content":{"rendered":"<p><span>&nbsp;I will present the main result from a paper by Takeoka and&nbsp;<\/span><span>Sasaki [PRA 78:022320, 2008], which says that to distinguish two&nbsp;coherent&nbsp;<\/span><span>quantum states of a single mode, there is a difference between the optimal&nbsp;<\/span><span>(Helstrom) measurement, which is non-linear, and what can be achieved&nbsp;<\/span><span>by Gaussian operations and classical information processing (GOCC). The&nbsp;<\/span><span>optimum strategy from the latter class&nbsp;is simply the homodyne measurement&nbsp;<\/span><span>of the quadrature direction&nbsp;along&nbsp;the line connecting the two phase space&nbsp;<\/span><span>expectations.<\/span><br \/><span>The gap is small, though, and even smaller when certain simple non-linear&nbsp;<\/span><span>optical elements are allowed. I then plan to discuss ideas for obtaining a&nbsp;<\/span><span>large gap&nbsp;between ALL measurements and GOCC, a kind of linear optical&nbsp;<\/span>data hiding.&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp;I will present the main result from a paper by Takeoka and&nbsp;Sasaki [PRA 78:022320, 2008], which says that to distinguish two&nbsp;coherent&nbsp;quantum states of a single mode, there is a difference between the optimal&nbsp;(Helstrom) measurement, which is non-linear, and what can be achieved&nbsp;by Gaussian operations and classical information processing (GOCC). The&nbsp;optimum strategy from the latter class&nbsp;is [&hellip;]<\/p>\n","protected":false},"author":20,"featured_media":0,"template":"","class_list":["post-986","seminar","type-seminar","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/seminar\/986","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\/20"}],"wp:attachment":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/media?parent=986"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}