{"id":4912,"date":"2022-03-10T13:44:12","date_gmt":"2022-03-10T16:44:12","guid":{"rendered":"https:\/\/sbfisica.org.br\/v1\/sbf\/2022\/03\/10\/fonons-opticos-controlaveis-por-campos-magneticos\/"},"modified":"2022-08-15T00:21:53","modified_gmt":"2022-08-15T03:21:53","slug":"fonons-opticos-controlaveis-por-campos-magneticos","status":"publish","type":"post","link":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/fonons-opticos-controlaveis-por-campos-magneticos\/","title":{"rendered":"F\u00f4nons \u00f3pticos control\u00e1veis por campos magn\u00e9ticos"},"content":{"rendered":"<p><img decoding=\"async\" data-src=\"images\/destaque-em-fisica\/2022\/destaque-2022-03-10.png\" alt=\"\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" \/>Aplicando um forte campo magn\u00e9tico em amostras de telureto de chumbo (PbTe), uma equipe internacional, com a participa\u00e7\u00e3o de pesquisadores brasileiros, observou um novo fen\u00f4meno envolvendo as vibra\u00e7\u00f5es coletivas dos \u00e1tomos, os f\u00f4nons. Os resultados foram publicados dia 15 de fevereiro, na Physical Review Letters.<\/p>\n<p>Um dos coautores principais do estudo, o professor Felix Hernandez, do Instituto de F\u00edsica da Universidade de S\u00e3o Paulo (IFUSP), explica no v\u00eddeo que o telureto de chumbo (PbTe) \u00e9 considerado um material muito importante para aplica\u00e7\u00f5es tecnol\u00f3gicas, especialmente devido \u00e0s suas excepcionais propriedades termoel\u00e9tricas, nas quais os f\u00f4nons tem um papel crucial.<\/p>\n<p><!--more--><\/p>\n<p><iframe style=\"display: block; margin-left: auto; margin-right: auto;\" title=\"YouTube video player\" data-src=\"https:\/\/www.youtube.com\/embed\/2oCTN2Coa6M\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" data-load-mode=\"1\"><\/iframe><\/p>\n<p><span style=\"background-color: inherit; color: inherit; font-family: inherit; font-size: 1rem;\">Os f\u00f4nons s\u00e3o vibra\u00e7\u00f5es coletivas dos \u00e1tomos da rede cristalina do material. Quando a oscila\u00e7\u00e3o dos \u00e1tomos da rede acontece em sincronia, os f\u00f4nons atuam transferindo calor pela rede, influenciando a condutividade t\u00e9rmica do telureto de chumbo. Mas esse n\u00e3o \u00e9 o \u00fanico modo de oscila\u00e7\u00e3o poss\u00edvel. Um feixe de luz laser com frequ\u00eancia da ordem de terahertz faz os \u00edons de tel\u00fario e chumbo do cristal oscilarem em dire\u00e7\u00f5es opostas, gerando outro tipo de f\u00f4non, capaz de influenciar as propriedades \u00f3pticas do material.\u00a0<\/span><\/p>\n<p>Quando os pesquisadores aplicam um forte campo magn\u00e9tico nas amostras de PbTe, os \u00edons ganham um movimento circular que, junto com a diferen\u00e7a de massa entre os \u00edons de Pb e Te, produz f\u00f4nons \u00f3pticos com um momento magn\u00e9tico e que ser\u00e3o circularmente polarizados. A componente circular do campo magn\u00e9tico externo girando em um sentido produz f\u00f4nons \u00f3pticos circularmente polarizados girando no sentido contr\u00e1rio, um fen\u00f4meno conhecido como dicro\u00edsmo circular magn\u00e9tico.<\/p>\n<p>Os experimentos foram realizados no laborat\u00f3rio do grupo do f\u00edsico Junichiro Kono, da Universidade Rice, Estados Unidos, pelo pesquisador de p\u00f3s-doutorado Andrey Baydin e por Felix Hernandez, da USP. Tamb\u00e9m participaram do estudo grupos te\u00f3ricos dos Estados Unidos e do Jap\u00e3o, para constru\u00e7\u00e3o do aparelho experimental, al\u00e9m de pesquisadores do Brasil, do Instituto Nacional de Pesquisas Espaciais (INPE), para a produ\u00e7\u00e3o das amostras.<\/p>\n<p>A pesquisa foi realizada com apoio financeiro do CNPq e da FAPESP.<\/p>\n<p><strong>Artigo cient\u00edfico<\/strong><br \/>\nMagnetic Control of Soft Chiral Phonons in PbTe<br \/>\nAndrey Baydin, Felix G. G. Hernandez, Martin Rodriguez-Vega, Anderson K. Okazaki, Fuyang Tay, G. Timothy Noe, II, Ikufumi Katayama, Jun Takeda, Hiroyuki Nojiri, Paulo H. O. Rappl, Eduardo Abramof, Gregory A. Fiete e Junichiro Kono<br \/>\n<a href=\"https:\/\/doi.org\/10.1103\/PhysRevLett.128.075901\">Phys. Rev. Lett. 128, 075901 \u2013 15 de fevereiro de 2022<br \/>\n<\/a><a href=\"https:\/\/arxiv.org\/abs\/2107.07616\">ArXiv:2107.07616<\/a><a href=\"https:\/\/doi.org\/10.1103\/PhysRevLett.128.075901\"><br \/>\n<\/a><\/p>\n<p><strong>Contato para imprensa<\/strong><br \/>\nIgor Zolnerkevic<br \/>\nAssessor de comunica\u00e7\u00e3o<br \/>\n<span id=\"cloakaea3a6d92c0b296f2c2656f3e15e66ed\"><span id=\"cloak36935a41aed49900fdfcd0ccc07756b0\"><span id=\"cloak1d0784f7944e77e5959d8acb3f4f841c\"><span id=\"cloak260329287650011057a9ea428c5d9667\"><span id=\"cloak70b06bc3011fdfd0bf25446e0b7febc2\"><span id=\"cloak6e91b9d3f8e87e4bc1b0aa101ab4faec\"><span id=\"cloakb4fb8d6e48379e9da5bb6f643ced88ca\"><span id=\"cloak0cafab7efee5686b4649f627df782102\"><span id=\"cloak16ea127c092c7641257ee108a4c02db5\"><span id=\"cloakbfb02956d181edbfde48338c6a26de04\"><span id=\"cloakdd2ffa7fbe353844aa302ac5b56c9d8d\"><span id=\"cloakcd6a2f8ba9c58f7915cd9858e4f6715b\"><span id=\"cloak7881b31ca4ca8c858bca5deda2759490\"><span id=\"cloaka1b234b5c1312839e9cb5149440f93dd\"><span id=\"cloakb46904c0dd26640555168eca35cf687e\"><span id=\"cloakab8a18b4788575a2fb004defede27223\"><span id=\"cloak3f76891238eeb85532c45d02f957727b\"><span id=\"cloak796eff52e85be4a4e9ac2d01e9770468\"><span id=\"cloak6c56a3169aedb00255530523c37f5ec6\"><span id=\"cloakf41b17c1fe162429965acf86a7a78745\"><span id=\"cloak99ca8e9374ab3f18d1379a33a136f095\"><span id=\"cloak32959540776525133bfda097c265956b\"><span id=\"cloak7c02ed46096391dc385965f86dbb9b24\"><span id=\"cloak3f6811053eb0e17d0e2b74919f51301a\"><span id=\"cloak258520f4717194dfc5d747907002c8f9\"><span id=\"cloakbd34a7c5e2bc2056fbee4aa77336bf6e\"><span id=\"cloak8eb44673fab2d827335949b56922b578\"><span id=\"cloak3b09f6b02815b1b1bec4750f39cb0880\"><span id=\"cloak86f5967951bde189a5c4a9a3a69df955\"><span id=\"cloak2b6ead48b2ab51e24efa86744faced80\"><span id=\"cloak18ea95729e7614f61f1c72ba9b73e4e5\"><span id=\"cloaka0031e32f0a8f748392f51856e99c354\"><span id=\"cloak41aa5aa49439d923ae5da3b418049dd8\"><span id=\"cloake1f52b7df2a60539b685b55ddbbd38ca\"><span id=\"cloak9b27e74b5f374c2634667b2bdf86d600\"><span id=\"cloakef6eba96fa77e934b1b62395c9bb3275\"><span id=\"cloakec13b66700c047076a55319d3418e15c\"><span id=\"cloakf08c39a763a17019adcc3a0246597f03\"><span id=\"cloakff810a6b774139f21b0128c4c4c6584f\"><span id=\"cloakccac4f890f002320b759eb1e9b915b4e\"><span id=\"cloak256c6aebf3beef560a35e2f1301b3e23\"><span id=\"cloak8c795a67310efc0ad4167c3825a142e2\"><span id=\"cloak18c514794cbfaf5fb17b5a19f5eb9c6c\"><span id=\"cloakc981a0dfe692b813ecf3df3fc33c9719\"><span id=\"cloakfc3f7bbb68ba01b628e3c62f87f19f42\"><span id=\"cloak5e447598ad3ced17f006dc7adae1d929\"><span id=\"cloak032b5b8e3e78b5de911dc54ad91dc1c6\"><span id=\"cloak5569f52ba4489b1e3247bb53481a89c5\"><span id=\"cloak37271e2e5d0634611c2f1d87444f6379\"><span id=\"cloak388adad93e4991029d4b1efae70fe0e4\"><span id=\"cloake18d291159bd11e2d168a2187db5b219\"><span id=\"cloak6cb97520ba1767ef80772480802f69e1\"><span id=\"cloakabc918bb4b5c60dcfed96ae7c5e0f941\"><span id=\"cloak86c9b871732573cc404d77134a9e55c2\"><span id=\"cloak81a21af2635bbd1ad6ed1ca15ef8cb43\"><span id=\"cloakc8f098ecfaa846e8429490acf30658af\"><span id=\"cloakb3d1ae543001e920759fe12449ab6549\"><span id=\"cloakc32b8afd5df8c62fe8d0998d56686040\"><a href=\"mailto:comunicacao@sbfisica.org.br\">comunicacao@sbfisica.org.br<\/a><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Aplicando um forte campo magn\u00e9tico em amostras de telureto de chumbo (PbTe), uma equipe internacional, com a participa\u00e7\u00e3o de pesquisadores brasileiros, observou um novo fen\u00f4meno envolvendo as vibra\u00e7\u00f5es coletivas dos \u00e1tomos, os f\u00f4nons. Os resultados foram publicados dia 15 de fevereiro, na Physical Review Letters. Um dos coautores principais do estudo, o professor Felix Hernandez, [&hellip;]<\/p>\n","protected":false},"author":8,"featured_media":16635,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[124],"tags":[],"class_list":["post-4912","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-destaque-em-fisica"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/posts\/4912","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/comments?post=4912"}],"version-history":[{"count":2,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/posts\/4912\/revisions"}],"predecessor-version":[{"id":16636,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/posts\/4912\/revisions\/16636"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/media\/16635"}],"wp:attachment":[{"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/media?parent=4912"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/categories?post=4912"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sbfisica.org.br\/v1\/sbf\/wp-json\/wp\/v2\/tags?post=4912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}