{"id":21071,"date":"2021-04-21T16:22:39","date_gmt":"2021-04-21T16:22:39","guid":{"rendered":"https:\/\/www.upjs.sk\/prirodovedecka-fakulta\/pracoviska\/ufv\/24725-2\/"},"modified":"2022-10-26T10:35:01","modified_gmt":"2022-10-26T10:35:01","slug":"24725-2","status":"publish","type":"cpt_pracoviska","link":"https:\/\/www.upjs.sk\/prirodovedecka-fakulta\/pracoviska\/ustavy-pf\/ufv\/ufv-st\/24725-2\/","title":{"rendered":"Interakcia na po\u017eiadanie \u2013 ex-so-tic(k\u00e1) s\u00fa\u010diastka"},"content":{"rendered":"
V\u00fdskumn\u00fd t\u00edm v zlo\u017een\u00ed:<\/strong>\u00a0Dr. Klaus Zollner, prof. Jaroslav Fabian z \u00dastavu teoretickej fyziky Univerzity v Regensburgu, a\u00a0RNDr. Martin Gmitra, PhD.<\/strong>\u00a0z \u00dastavu fyzik\u00e1lnych vied PF UPJ\u0160 v Ko\u0161iciach<\/em>,\u00a0navrhol a sk\u00famal spintronick\u00fa s\u00fa\u010diastku<\/strong>, ktorej fyzik\u00e1lne vlastnosti s\u00fa kontrolovan\u00e9 elektrick\u00fdm po\u013eom. V\u00fdsledky autori publikovali v prest\u00ed\u017enom vedeckom \u010dasopise\u00a0Physical Review Letters.<\/em>\u00a0\u0160t\u00fadia Zollner et al. (2020) prezentuje n\u00e1vrh a vlastnosti vrstevnat\u00e9ho sendvi\u010dov\u00e9ho syst\u00e9mu, tzv. ex-so-tic s\u00fa\u010diastky, ktor\u00e1 predstavuje prototyp pre tvorbu nov\u00fdch spintronick\u00fdch zariaden\u00ed kon\u0161truovan\u00fdch z dvojrozmern\u00fdch materi\u00e1lov.\u00a0<\/p>\n <\/p>\n Obr. 1\u00a0<\/strong>At\u00f3mov\u00fd model re\u00e1lnej \u0161trukt\u00fary ex-so-tic(kej) s\u00fa\u010diastky pre ab-initio v\u00fdpo\u010dty a fyzik\u00e1lny mechanizmus proxim\u00e1lnych efektov ved\u00facich k prep\u00ednaniu v\u00fdmennej a spin-orbit\u00e1lnej interakcie.<\/p>\n Zollner et al. (2020) vych\u00e1dzali z predpokladu<\/strong>, \u017ee ka\u017ed\u00fd materi\u00e1l je s\u00faborom at\u00f3mov s ist\u00fdmi fyzik\u00e1lnymi vlastnos\u0165ami, ktor\u00e9 s\u00fa mu dan\u00e9 pri jeho zrode. Pomocou fyzik\u00e1lnych interakci\u00ed mo\u017eno ovplyvni\u0165 mnoh\u00e9 charakteristiky materi\u00e1lov zmenou priestorov\u00e9ho usporiadania at\u00f3mov a v\u00fdberom spr\u00e1vneho typu at\u00f3mov. Vedci \u010dasto stoja pred v\u00fdzvami motivovan\u00fdmi technologick\u00fdmi po\u017eiadavkami na vytvorenie tak\u00fdch fyzik\u00e1lnych syst\u00e9mov, ktor\u00e9 by raz boli magnetom a inokedy polovodi\u010dom pod\u013ea toho, ako je \u201eoto\u010den\u00fd kontroln\u00fd prep\u00edna\u010d\u201c. V spom\u00ednanom pr\u00edpade by ale muselo \u00eds\u0165 o prep\u00edna\u010d, ktor\u00fdm by bolo mo\u017en\u00e9 zmeni\u0165 fundament\u00e1lnu symetriu syst\u00e9mu \u2013 symetriu reverzie \u010dasu, ktor\u00e1 je naru\u0161en\u00e1 v magnete, ale ost\u00e1va zachovan\u00e1 v polovodi\u010di.<\/p>\n K\u013e\u00fa\u010dom k r\u00e9busu je zmena uhla poh\u013eadu na probl\u00e9m<\/strong>. Dvojrozmern\u00e9 materi\u00e1ly, niekedy iba jeden at\u00f3m tenk\u00e9, m\u00f4\u017eu byt poukladan\u00e9 do viacvrstvov\u00fdch \u0161trukt\u00far, v ktor\u00fdch s\u00fa navz\u00e1jom viazan\u00e9 slab\u00fdmi van der Waalsov\u00fdmi interakciami. To umo\u017en\u00ed, \u017ee si jednotliv\u00e9 materi\u00e1ly zachovaj\u00fa svoje \u0161pecifick\u00e9 vlastnosti vo svojich rovin\u00e1ch, ale m\u00f4\u017eu pren\u00e1\u0161a\u0165 interakcie medzi rovinami. Na druhej strane sa tu otv\u00e1ra mo\u017enos\u0165 prep\u00edna\u0165 medzi ich vlastnos\u0165ami cez modifikovanie Fermiho plochy pomocou nalo\u017een\u00e9ho nap\u00e4tia (kontrolnej p\u00e1\u010dky). Fermiho plocha je s\u00fabor elektr\u00f3nov\u00fdch stavov, ktor\u00e9 s\u00fa v preva\u017enej miere zodpovedn\u00e9 za \u0161pecifick\u00e9 vlastnosti materi\u00e1lu odzrkad\u013euj\u00fac z\u00e1rove\u0148 fundament\u00e1lne symetrie.\u00a0<\/p>\n Navrhnut\u00e1 ex-so-tic-k\u00e1 s\u00fa\u010diastka pozost\u00e1va<\/strong>\u00a0z dvojvrstvy graf\u00e9nu (uhl\u00edka), dvojrozmern\u00e9ho feromagnetu Cr2<\/sub>Ge2<\/sub>Te6<\/sub> a monovrstvy polovodi\u010da WS2<\/sub>. Mo\u017enos\u0165 prep\u00edna\u0165 medzi v\u00fdmennou (\u201eex\u201c \u2013 exchange) interakciou a spinovo-orbit\u00e1lnou (\u201eso\u201c \u2013 spin-orbit) interakciou na po\u017eiadanie pomocou elektrick\u00e9ho po\u013ea autori preuk\u00e1zali pomocou teoretick\u00fdch ab-initio v\u00fdpo\u010dtov.\u00a0<\/p>\n Odkaz na publikovan\u00fa \u0161t\u00fadiu:<\/strong><\/p>\n K. Zollner, M. Gmitra, J. Fabian 2020. Swapping Exchange and Spin-Orbit Coupling in 2D van der Waals Heterostructures. Physical Review Letters 125, 196402. https:\/\/doi.org\/10.1103\/PhysRevLett.125.196402<\/p>\n","protected":false},"author":1,"featured_media":16453,"parent":20238,"menu_order":4,"template":"","meta":{"_acf_changed":false,"_editorskit_title_hidden":false,"_editorskit_reading_time":0,"_editorskit_is_block_options_detached":false,"_editorskit_block_options_position":"{}"},"categories":[],"tags":[],"tax_aktuality":[],"class_list":["post-21071","cpt_pracoviska","type-cpt_pracoviska","status-publish","has-post-thumbnail","hentry"],"acf":{"acf_link_na_externy_obsah":""},"yoast_head":"\n