{"id":1251,"date":"2020-01-08T20:48:21","date_gmt":"2020-01-08T20:48:21","guid":{"rendered":"http:\/\/lptms.u-psud.fr\/nicolas_pavloff\/?page_id=1251"},"modified":"2023-09-03T08:11:23","modified_gmt":"2023-09-03T08:11:23","slug":"analogous-hawking-radiation","status":"publish","type":"page","link":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/research\/analogous-hawking-radiation\/","title":{"rendered":"Analogous Hawking radiation"},"content":{"rendered":"<p>Confronting the predictions of general relativity and quantum mechanics, Hawking showed in 1973 that black holes are not completely black, but emit a faint radiation. However, this radiation is too weak to be detected in the astrophysical context. We can circumvent this difficulty because we are now able to realize analogous systems in the lab: the flow of some quantum fluids emit a sonic analogue of the Hawking radiation.<\/p>\n<p><a href=\"\/nicolas_pavloff\/files\/2020\/02\/schema_TrouNoir.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1362 size-full\" src=\"\/nicolas_pavloff\/files\/2020\/02\/schema_TrouNoir.jpg\" alt=\"\" width=\"641\" height=\"223\" srcset=\"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2020\/02\/schema_TrouNoir.jpg 641w, http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2020\/02\/schema_TrouNoir-300x104.jpg 300w\" sizes=\"auto, (max-width: 641px) 100vw, 641px\" \/><\/a><\/p>\n<p>In a series of works I participated to theoretically analyze some experimental platforms making it possible to realize an analogous black hole in a quantum fluid known as a \u00ab\u00a0Bose-Einstein condensate\u00a0\u00bb. See a <a href=\"http:\/\/archives.cnrs.fr\/inp\/article\/484\">popularizing note<\/a> on entanglement in acoustic Hawking radiation and also a <a href=\"https:\/\/www.canal-u.tv\/video\/scavo\/les_trous_noirs_acoustiques.49705\">short movie<\/a> (in french) by R. Drot and M. Relid (service communication de l\u2019Universit\u00e9 Paris-Sud) on acoustic black holes, from which the picture below is extracted.<\/p>\n<p><a href=\"\/nicolas_pavloff\/files\/2020\/02\/Screenshot_Mach-Cone.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-1342\" src=\"\/nicolas_pavloff\/files\/2020\/02\/Screenshot_Mach-Cone-300x169.png\" alt=\"\" width=\"450\" height=\"253\" srcset=\"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2020\/02\/Screenshot_Mach-Cone-300x169.png 300w, http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2020\/02\/Screenshot_Mach-Cone-768x431.png 768w, http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2020\/02\/Screenshot_Mach-Cone.png 858w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/a><\/p>\n<table class=\" aligncenter\" style=\"width: 962px;\">\n<tbody>\n<tr>\n<td style=\"width: 952px; background-color: #f5d7d7; text-align: left;\" scope=\"row\">Although they widely differ in intensity and wavelength, the light emitted by a usual star and the Hawking radiation of a gravitational black hole have an important feature in common: their spectra are both fixed by their surface temperature and obey the so-called Planck&rsquo;s law.In a <a href=\"\/nicolas_pavloff\/files\/2020\/02\/PRL_IP_2020.pdf\">work<\/a> together with Mathieu Isoard, we theoretically reproduce recent experimental results and challenge their interpretation by arguing that, at variance with what occurs in a gravitational black hole, the analogous radiation of a Bose-Einstein condensate is not planckian. We also propose an experimental verification of this claim.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>In a work with M. Isoard, N. Millazo and O. Giraud we studied bi- and tri-partite entanglement in an analog black hole realized in a Bose-Einstein condensate. The description of the localization of entanglement in the system suggests a quantum circuit model for the analog system: A parametric down-conversion process (e.g. triggered by a classical pump incident onto a nonlinear crystal) generates a two-mode squeezed vaccum state.\u00a0 One of the modes is the Partner, the other being sent on a beam-splitter generates the Hawking mode and a new mode (typical in dispersive analogues) we denote as Companion. See Fig. below:<\/p>\n<p style=\"text-align: left;\"><a href=\"\/nicolas_pavloff\/files\/2021\/10\/PDC_BH.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-1616 aligncenter\" src=\"\/nicolas_pavloff\/files\/2021\/10\/PDC_BH-300x170.jpg\" alt=\"\" width=\"618\" height=\"350\" srcset=\"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2021\/10\/PDC_BH-300x170.jpg 300w, http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2021\/10\/PDC_BH-768x436.jpg 768w, http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/files\/2021\/10\/PDC_BH.jpg 939w\" sizes=\"auto, (max-width: 618px) 100vw, 618px\" \/><\/a><\/p>\n<p>This model suggested a new way to define the analogue Hawking temperature, yielding a result in much better agreement with the gravitational paradigm than previous definitions. Details in <a href=\"\/nicolas_pavloff\/files\/2021\/12\/PRA2021.pdf\">PhysRevA.104.063302<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Confronting the predictions of general relativity and quantum mechanics, Hawking showed in 1973 that black holes are not completely black, but emit a faint radiation. However, this radiation is too weak to be detected in the astrophysical context. We can &hellip; <a href=\"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/research\/analogous-hawking-radiation\/\">Continuer la lecture <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":5,"featured_media":0,"parent":1248,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1251","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/pages\/1251","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/comments?post=1251"}],"version-history":[{"count":52,"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/pages\/1251\/revisions"}],"predecessor-version":[{"id":1709,"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/pages\/1251\/revisions\/1709"}],"up":[{"embeddable":true,"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/pages\/1248"}],"wp:attachment":[{"href":"http:\/\/www.lptms.universite-paris-saclay.fr\/nicolas_pavloff\/wp-json\/wp\/v2\/media?parent=1251"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}