{"id":6077,"date":"2026-10-19T09:48:26","date_gmt":"2026-10-19T09:48:26","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsfyrirlestur-i-efnafraedi-dr-gideon-muller\/"},"modified":"2026-10-19T09:48:26","modified_gmt":"2026-10-19T09:48:26","slug":"doktorsfyrirlestur-i-efnafraedi-dr-gideon-muller","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsfyrirlestur-i-efnafraedi-dr-gideon-muller\/","title":{"rendered":"Doktorsfyrirlestur \u00ed efnafr\u00e6\u00f0i – Dr. Gideon M\u00fcller"},"content":{"rendered":"
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Doktorsefni:<\/strong>\u00a0Dr. Gideon M\u00fcller\u00a0<\/p>\n

Heiti ritger\u00f0ar:\u00a0Skilvirkar a\u00f0fer\u00f0ir fyrir at\u00f3mskala t\u00f6lvureikninga \u00e1 spunakerfum og ranns\u00f3knir \u00e1 sta\u00f0bundnum segul\u00e1st\u00f6ndum.<\/p>\n

Um er a\u00f0 r\u00e6\u00f0a sameiginlega gr\u00e1\u00f0u H\u00cd og RWTH Aachen h\u00e1sk\u00f3la.\u00a0Vinnan \u00ed \u00de\u00fdskalandi f\u00f3r fram \u00ed ranns\u00f3knast\u00f6\u00f0inni \u00ed J\u00fclich.<\/p>\n

Gideon M\u00fcller var\u00f0i doktorsritger\u00f0 s\u00edna vi\u00f0 RWTH Aachen h\u00e1sk\u00f3la \u00feann 2. september. H\u00e9r er \u00fev\u00ed um doktorsfyrirlestur a\u00f0 r\u00e6\u00f0a.<\/p>\n

Andm\u00e6landi:\u00a0Carsten Honerkamp, pr\u00f3fessor \u00ed e\u00f0lisfr\u00e6\u00f0i vi\u00f0 RWTH Aachen h\u00e1sk\u00f3la.\u00a0<\/p>\n

Lei\u00f0beinendur:\u00a0<\/p>\n

Hannes J\u00f3nsson, pr\u00f3fessor \u00ed e\u00f0lisefnafr\u00e6\u00f0i vi\u00f0 H\u00cd og\u00a0Stefan Bl\u00fcgel, pr\u00f3fessor \u00ed e\u00f0lisfr\u00e6\u00f0i vi\u00f0 RWTH Aachen h\u00e1sk\u00f3la og forst\u00f6\u00f0uma\u00f0ur \u00a0Peter Gr\u00fcnberg stofnunarinnar og\u00a0Institute for Advanced Simulation vi\u00f0 ranns\u00f3knastofnunina \u00ed J\u00fclich.<\/p>\n

Doktorsnefnd:\u00a0<\/p>\n

Unnar Arnalds, v\u00edsindama\u00f0ur \u00e1 E\u00f0lisfr\u00e6\u00f0istofu Raunv\u00edsindastofnunar,\u00a0Stefan Bl\u00fcgel og Hannes J\u00f3nsson.<\/p>\n

Doktorsv\u00f6rn st\u00fdr\u00f0i:\u00a0Markus Morgenstern,\u00a0pr\u00f3fessor \u00ed e\u00f0lisfr\u00e6\u00f0i vi\u00f0 RWTH Aachen h\u00e1sk\u00f3la.<\/p>\n

\u00c1grip:<\/strong><\/p>\n

Sta\u00f0bundin segul\u00e1st\u00f6nd, svokalla\u00f0ir einfarar, hafa agnaeiginleika og eru miki\u00f0 ranns\u00f6ku\u00f0 \u00ed dag. H\u00e6gt v\u00e6ri a\u00f0 nota \u00feau \u00e1 \u00fdmsan h\u00e1tt en \u00feau er l\u00edka \u00e1hugavert a\u00f0 kanna grundvallar eiginleika \u00feeirra. A\u00f0 mestu leiti er h\u00e6gt a\u00f0 l\u00fdsa sl\u00edkum \u00e1st\u00f6ndum me\u00f0 klass\u00edskum spuna-grindar l\u00edk\u00f6num.\u00a0 Mikilv\u00e6gt er a\u00f0 hafa skilvirkar a\u00f0fer\u00f0ir til a\u00f0 reikna \u00fat hina \u00fdmsu eiginleika svo sem varmafr\u00e6\u00f0ilegan st\u00f6\u00f0ugleika, l\u00edft\u00edma, kr\u00edt\u00edskan hra\u00f0a, eiginh\u00e6tti o.sv.frv. \u00deessi ritger\u00f0 fjallar um \u00fer\u00f3un a\u00f0fer\u00f0afr\u00e6\u00f0i, innsetningu og beitingu n\u00fds hugb\u00fana\u00f0ar fyrir t\u00f6lvureikninga \u00e1 spunakerfum \u00e1 at\u00f3mskala.<\/p>\n

Til a\u00f0 komast umfram \u00fea\u00f0 sem h\u00e6gt er a\u00f0 gera me\u00f0 algengum a\u00f0fer\u00f0um svo sem Monte Carlo og Landau-Lifshitz-Gilbert (LLG) t\u00edmaferlum, byggir ritger\u00f0in \u00e1 heilsteyptri framsetningu \u00e1 ‘geodesic nudged elastic band’<\/p>\n

(GNEB) a\u00f0fer\u00f0inni og kj\u00f6rsveifilsn\u00e1lgun \u00e1 virkjunar\u00e1standskenningunni (HTST). ‘Minimum mode following’ (MMF) a\u00f0fer\u00f0in til a\u00f0 finna fyrsta stigs s\u00f6\u00f0ulpunkta er \u00fatv\u00edkku\u00f0 fyrir segulkerfi. Sl\u00edkar s\u00f6\u00f0ulpunktaleitir eru mikilv\u00e6gar til a\u00f0 finna m\u00f6gulega hvarfganga yfir breytingar \u00far einu segul\u00e1standi \u00ed anna\u00f0 sem er nau\u00f0synlegur undanfari \u00feess a\u00f0 meta hvarfhra\u00f0a og \u00fear me\u00f0 l\u00edft\u00edma segul\u00e1standa. Me\u00f0 MMF a\u00f0fer\u00f0inni var fundinn hvarfgangur \u00fear sem skyrmeind skiptist upp \u00ed tv\u00e6r skyrmeindir, e\u00f0a \u00f6fugt – a\u00f0 tv\u00e6r skyrmeindir renni saman \u00ed eina – og s\u00fdnt fram \u00e1 a\u00f0 h\u00e6gt v\u00e6ri a\u00f0 kalla fram sl\u00edkan hvarfgang \u00ed LLG reikningum \u00e1 t\u00edmaframvindu \u00feegar beitt er segulsvi\u00f0sp\u00falsi.<\/p>\n

Hinar \u00fdmsu a\u00f0fer\u00f0ir sem fjalla\u00f0 er um \u00ed ritger\u00f0inni hafa veri\u00f0 innleiddar \u00ed n\u00fdjum hugb\u00fana\u00f0arpakka. Me\u00f0 skriftum og sj\u00f3nr\u00e6nu vi\u00f0m\u00f3ti sem og \u00f6fugri raunt\u00edma myndgerfingu er au\u00f0velt a\u00f0 n\u00fdta hinar \u00fdmsu a\u00f0fer\u00f0ir og n\u00fdta s\u00e9r kosti hverrar um sig. Innsetningunni, \u00fear me\u00f0 samhli\u00f0avinnslunni, er l\u00fdst sem og lykil eiginleikum.<\/p>\n

Hugb\u00fana\u00f0inum er beitt \u00e1 \u00fdmis krefjandi verkefni sem tengjast tv\u00ed- og \u00fer\u00edv\u00ed\u00f0um kerfum. \u00cd tv\u00edv\u00ed\u00f0um kerfum eru skyrmeindir rannsaka\u00f0ar me\u00f0 GNEB a\u00f0fer\u00f0inni og GNEB a\u00f0fer\u00f0in notu\u00f0 til a\u00f0 finna skiptingu \u00e1 skyrmeind. Fyrir \u00fer\u00edv\u00ed\u00f0 kerfi er s\u00fdnt fram \u00e1 a\u00f0 \u00fdmis fl\u00f3kin segulkerfi geta myndast, \u00fear me\u00f0 n\u00fdtt \u00fer\u00edv\u00edtt sgulkerfi sen vi\u00f0 k\u00f6llum ‘globule’. \u00deetta \u00e1stand felur \u00ed s\u00e9r tv\u00f6 tengd einskaut, sem einnig eru k\u00f6llu\u00f0 Bloch punktar, og \u00fea\u00f0 getur veri\u00f0 st\u00f6\u00f0ugt yfir m\u00f6rg stikugildi og vi\u00f0 \u00fdmsar a\u00f0st\u00e6\u00f0ur.<\/p>\n

Hub\u00fana\u00f0urinn sem l\u00fdst er \u00ed ritger\u00f0inni gerir at\u00f3mskala reikninga \u00e1 segulkerfum au\u00f0velda og felur \u00ed s\u00e9r st\u00f3rt skref til a\u00f0 n\u00fdt\u00edmav\u00e6\u00f0a t\u00f3l sem h\u00e6gt er a\u00f0 nota \u00ed t\u00f6lvureikningum \u00e1 segulkerfum. Hann sameinar kosti \u00feess a\u00f0 vera au\u00f0veldur \u00ed notkin og eykur a\u00f0gengi a\u00f0 n\u00fdrri- og endurb\u00e6ttri a\u00f0fer\u00f0afr\u00e6\u00f0i.<\/p>\n

Um doktorsefni\u00f0:\u00a0\u00a0<\/strong><\/p>\n

Gideon M\u00fcller lauk B.S. pr\u00f3fi \u00ed e\u00f0lisfr\u00e6\u00f0i RWTH Aachen h\u00e1sk\u00f3lann 20. september 2013.<\/p>\n<\/div><\/div>","protected":false},"featured_media":1771,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-09-13T13:00:00+00:00","_phd_date_end":"2019-09-13T14:30:00+00:00","_phd_location":"\u00dej\u00f3\u00f0minjasafn \u00cdslands","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Skilvirkar a\u00f0fer\u00f0ir fyrir at\u00f3mskala t\u00f6lvureikninga \u00e1 spunakerfum og ranns\u00f3knir \u00e1 sta\u00f0bundnum segul\u00e1st\u00f6ndum","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsfyrirlestur_i_efnafraedi_dr_gideon_muller","_phd_source_node_id":"323463","_phd_source_type":"vidburdir","_phd_member_id":448,"footnotes":""},"phd_school":[101,93],"phd_discipline":[102],"class_list":["post-6077","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-raunvisindadeild","phd_school-verkfraedi-og-natturuvisindasvid","phd_discipline-phd-i-efnafraedi"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6077","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6077\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/1771"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6077"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6077"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6077"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}