{"id":1257,"date":"2022-03-02T09:59:29","date_gmt":"2022-03-02T07:59:29","guid":{"rendered":"https:\/\/webs.uab.cat\/giq\/seminar\/filter-functions-in-quantum-phase-space-representations\/"},"modified":"2022-03-02T09:59:29","modified_gmt":"2022-03-02T07:59:29","slug":"filter-functions-in-quantum-phase-space-representations","status":"publish","type":"seminar","link":"https:\/\/webs.uab.cat\/giq\/seminar\/filter-functions-in-quantum-phase-space-representations\/","title":{"rendered":"Filter functions in quantum phase space representations."},"content":{"rendered":"<p>Continuous-variable (CV) representation of quantum mechanics plays&nbsp;a major role in quantum information theory and quantum optics, espe-&nbsp;cially in quantum&nbsp;state and process tomography. As an example, one&nbsp;might consider inferring the non-classicality of an unknown state, based on&nbsp;whether or not it can be written as&nbsp;a statistical mixture of classical (coher-&nbsp;ent) states. However, there is a major challenge here: the weight function&nbsp;(P-function) is a highly singular function for&nbsp;most cases. Here is where the&nbsp;concept of filtering is useful. It is possible to filter the Fourier transform of&nbsp;the P-function (normally-ordered characteristic&nbsp;function) such that the P-&nbsp;function becomes regularized, and also reveals the non-classicality of the&nbsp;original state as negative values. However, there are two&nbsp;subjects that&nbsp;remained open. First, a cohesive mathematical requirements to build a&nbsp;physical filter, and second, how much resemblance exists between the orig-&nbsp;inal state and the filtered state. These two questions are addressed by the&nbsp;work that will be explained in the talk&nbsp;(<a href=\"https:\/\/us02web.zoom.us\/j\/87205372932?pwd=NFluMkxpMGgwWnBIRytib1BTZ3Z6UT09\">Zoom link<\/a>)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Continuous-variable (CV) representation of quantum mechanics plays&nbsp;a major role in quantum information theory and quantum optics, espe-&nbsp;cially in quantum&nbsp;state and process tomography. As an example, one&nbsp;might consider inferring the non-classicality of an unknown state, based on&nbsp;whether or not it can be written as&nbsp;a statistical mixture of classical (coher-&nbsp;ent) states. However, there is a major challenge [&hellip;]<\/p>\n","protected":false},"author":20,"featured_media":0,"template":"","class_list":["post-1257","seminar","type-seminar","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/webs.uab.cat\/giq\/wp-json\/wp\/v2\/seminar\/1257","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=1257"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}