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142432, Chernogolovka, Moscow region acad. Semenov prosp., 1a |
119334, Moscow Kosygin st., 2 |
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Phone: ++7-495-702-93-17 Fax: ++7-495-702-93-17 |
Phone: ++7-495-137-32-44 Fax: ++7-495-938-20-77 |
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Department of quantum mesoscopics: seminar, Friday, November 28, 2025, ITF, 3:00 pm Nazar Sichuk Manipulation of Néel-type skyrmions by the non-uniform electric field My izuchaem teoreticheski vozmozhnost' upravleniya skirmionami tipa Neelya s pomoshch'yu neodnorodnogo elektricheskogo polya, istochnikom kotorogo sluzhit tonkii zaryazhennyi zond. Elektricheskoe pole deistvuet na neodnorodnuyu namagnichennost' blagodarya magnitoelektricheskomu effektu, chto bylo predskazano eshche v 1980kh, no tol'ko nedavno podverzhdeno v eksperimente: pole privodit k smeshcheniyu domennykh stenok i rozhdeniyu domenov. Ispol'zuya analiticheskii podkhod, my pokazyvaem, chto etot zhe effekt dolzhen privodit' v dvizhenie skirmiony, izmenyat' ikh razmer, a takzhe sozdavat' i unichtozhat' ikh. Krome togo, elektricheskoe pole mozhet sozdavat' i podderzhivat' sushchestvovanie skirmionov otritsatel'noi kiral'nosti, a takzhe skirmioniumov. My detal'no issledovali usloviya i znacheniya parametrov, pri kotorykh mozhno realizovat' vysheukazannoe, i sostavili fazovuyu diagrammu v koordinatakh "rasstoyanie do zonda - intensivnost' polya", pokazyvayushchuyu sootvetstvuyushchie vozmozhnosti. Krome togo, my predlagaem teoreticheskii proekt ustroistva, v kotorom neskol'ko zondov mogut peremeshchat', sozdavat' i unichtozhat' skirmiony. Analiticheskie rezul'taty verifitsirovany chislennym mikromagnitnym modelirovanie. |
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Department of quantum mesoscopics: seminar, Friday, November 21, 2025, ITF, 3:00 pm Zaur Alisultanov (MFTI) Indutsirovannye besporyadkom topologicheskie perekhody v mul'tisloinom topologicheskom izolyatore Ispol'zuya prostuyu model' Burkova-Balentsa, my issledovali vliyanie nemagnitnogo besporyadka na elektronnye sostoyaniya mnogosloinoi struktury, sostoyashchei iz sloev kak topologicheskikh, tak i obychnykh dielektrikov. My poluchili fazovye diagrammy v zavisimosti ot urovnya besporyadka, pokazyvaya, chto nemagnitnyi besporyadok mozhet indutsirovat' perekhody mezhdu razlichnymi topologicheskimi fazami. Dalee, my issledovali elektronnye svoistva mnogosloinogo topologicheskogo izolyatora (MTI) v usloviyakh nediagonal'nogo besporyadka, kogda parametry mezhsloinogo tunnelirovaniya fluktuiruyut ot sloya k sloyu. Snachala my reshili zadachu dlya edinichnogo nediagonal'nogo defekta, pri kotorom v sisteme prisutstvuet odin sloi s tunnel'nym parametrom, otlichnym ot ostal'nykh. Takoi defekt indutsiruet svyazannoe sostoyanie vnutri zapreshchennoi zony. Zavisimost' energii etogo sostoyaniya ot sily vozmushcheniya sushchestvenno razlichaetsya v trivial'noi i topologicheskoi fazakh MTI, chto delaet takuyu zavisimost' universal'nym lokal'nym indikatorom topologicheskogo poryadka. Ispol'zuya prostoe diagrammnoe razlozhenie my vychislili plotnost' sostoyanii (PS) dlya chetyrekh topologicheskikh faz, realizuemykh v etoi sisteme: normal'nyi izolyator, topologicheskii izolyator, polumetall Veilya i faza anomal'nogo kvantovogo effekta Kholla (AKEKh). Nediagonal'nyi besporyadok porozhdaet novye ob'emnye sostoyaniya v shcheli i mozhet privesti k razrusheniyu topologicheskikh faz. Nakonets, my izuchili vliyanie nediagonal'nogo besporyadka na lokalizatsiyu kraevykh mod v MTI. My otsenili dlinu lokalizatsii dlya trekh raspredelenii besporyadka: ravnomernogo, gaussova i lorentseva. Nediagonal'nyi besporyadok sokhranyaet kiral'nost', no pri etom mozhet sposobstvovat' delokalizatsii kraevykh mod i tunnelirovaniyu mezhdu nimi, podryvaya topologicheskuyu zashchitu. My vychislili popravku k prodol'noi kraevoi provodimosti, voznikayushchuyu iz-za tunnel'nykh effektov, i pokazali, chto takoi besporyadok mozhet vyzyvat' otklonenie kraevoi provodimosti ot kvantovannogo znacheniya. Z.Z. Alisultanov, A. Kudlis, Phys. Rev. B 109, 165141 (2024) Z.Z. Alisultanov, A. Kudlis, Phys. Rev. B 112, 205108 (2025) |