Cov kws tshawb fawb ntawm NTNU tab tom qhia txog cov khoom siv sib nqus ntawm cov nplai me me los ntawm kev tsim cov yeeb yaj kiab nrog kev pab los ntawm qee cov duab X-ray ci ntsa iab heev.
Erik Folven, tus thawj coj ntawm pawg oxide electronics ntawm NTNU's Department of Electronic Systems, thiab cov npoj yaig los ntawm NTNU thiab Ghent University hauv Belgium tau tawm mus saib seb cov micromagnets nyias-zaj duab xis hloov pauv li cas thaum raug cuam tshuam los ntawm lub zog magnetic sab nraud. Cov haujlwm, ib feem tau txais nyiaj los ntawm NTNU Nano thiab Pawg Neeg Tshawb Fawb ntawm Norway, tau luam tawm hauv phau ntawv xov xwm Physical Review Research.
Cov hlau nplaum me me
Einar Standal Digernes tau tsim cov hlau nplaum me me uas siv rau hauv kev sim.
Cov hlau nplaum me me, tsim los ntawm NTNU Ph.D. tus neeg sib tw Einar Standal Digernes, tsuas yog ob micrometers dav thiab faib ua plaub thaj chaw peb ceg, txhua tus muaj qhov sib txawv sib txawv taw tes rau sab laug lossis sab xis nyob ib puag ncig cov hlau nplaum.
Hauv qee cov khoom siv sib nqus, cov pab pawg me me ntawm cov atoms sib koom ua ke rau hauv thaj chaw hu ua domains, uas txhua lub electrons muaj tib qho kev sib nqus.
Hauv cov hlau nplaum NTNU, cov cheeb tsam no ntsib ntawm qhov chaw nruab nrab - lub vortex core - qhov twg lub zog sib nqus taw qhia ncaj qha rau hauv lossis tawm ntawm lub dav hlau ntawm cov khoom.
"Thaum peb siv lub zog sib nqus, ntau dua thiab ntau dua ntawm cov cheeb tsam no yuav taw tes rau tib qho kev taw qhia," Folven hais. "Lawv tuaj yeem loj hlob thiab lawv tuaj yeem me me, thiab tom qab ntawd lawv tuaj yeem sib koom ua ke."
Cov electrons yuav luag ntawm qhov ceev ntawm lub teeb
Pom qhov no tshwm sim tsis yooj yim. Cov kws tshawb fawb tau coj lawv cov micromagnets mus rau 80m-dav donut-puab synchrotron, hu ua BESSY II, hauv Berlin, qhov chaw uas cov electrons raug nrawm kom txog thaum lawv mus ncig ntawm qhov ceev ntawm lub teeb. Cov electrons uas txav mus sai sai ces tso tawm cov duab X-rays ci ntsa iab heev.
"Peb siv cov duab X-ray no thiab siv lawv ua lub teeb hauv peb lub tshuab tsom iav," Folven hais.
Vim tias cov electrons ncig lub synchrotron hauv cov pawg sib cais los ntawm ob nanoseconds, cov duab X-rays uas lawv tso tawm los ua cov pulses meej.
Lub tshuab tsom iav X-ray uas siv scanning transmission, los yog STXM, siv cov duab X-ray no los tsim ib daim duab ntawm cov qauv sib nqus ntawm cov khoom. Los ntawm kev sib txuas cov duab no ua ke, cov kws tshawb fawb tuaj yeem tsim ib zaj yeeb yaj kiab uas qhia txog seb lub micromagnet hloov pauv li cas raws sijhawm.
Nrog kev pab los ntawm STXM, Folven thiab nws cov npoj yaig tau cuam tshuam lawv cov micromagnets nrog lub zog tam sim no uas tsim lub teb magnetic, thiab pom cov cheeb tsam hloov pauv thiab lub vortex core txav ntawm qhov chaw.
"Koj muaj ib lub hlau nplaum me me heev, thiab tom qab ntawd koj muab nws thawb thiab sim xav txog nws thaum nws rov qab los," nws hais. Tom qab ntawd, lawv pom lub plawv rov qab mus rau nruab nrab - tab sis raws txoj kev nkhaus, tsis yog txoj kab ncaj.
"Nws yuav zoo li seev cev rov qab mus rau hauv nruab nrab," Folven hais.
Ib qho kev poob thiab nws dhau lawm
Qhov ntawd yog vim lawv kawm txog cov ntaub ntawv epitaxial, uas tau tsim rau saum cov substrate uas tso cai rau cov kws tshawb fawb kho cov khoom ntawm cov khoom, tab sis yuav thaiv cov duab X-ray hauv STXM.
Ua haujlwm hauv NTNU NanoLab, cov kws tshawb fawb tau daws qhov teeb meem substrate los ntawm kev faus lawv cov micromagnet hauv qab ib txheej ntawm cov pa roj carbon los tiv thaiv nws cov khoom sib nqus.
Tom qab ntawd lawv ua tib zoo thiab meej meej txiav cov substrate hauv qab nrog lub teeb ci ntsa iab ntawm gallium ions kom txog thaum tsuas yog ib txheej nyias heev xwb. Cov txheej txheem ua haujlwm hnyav tuaj yeem siv sijhawm yim teev rau ib qho qauv - thiab ib qho kev ua yuam kev tuaj yeem ua rau muaj kev puas tsuaj loj heev.
"Qhov tseem ceeb yog tias, yog tias koj tua lub zog magnetism, peb yuav tsis paub qhov ntawd ua ntej peb zaum hauv Berlin," nws hais. "Lub tswv yim yog, tau kawg, coj ntau dua ib qho qauv."
Txij li cov physics yooj yim mus rau cov khoom siv yav tom ntej
Zoo siab uas nws ua haujlwm tau zoo, thiab pab neeg tau siv lawv cov qauv uas tau npaj zoo los qhia txog seb thaj chaw ntawm lub micromagnet loj hlob thiab me zuj zus li cas. Lawv kuj tau tsim cov kev sim ua hauv computer kom nkag siab zoo dua txog lub zog twg ua haujlwm.
Ntxiv rau kev txhim kho peb txoj kev paub txog physics yooj yim, kev nkag siab txog magnetism ua haujlwm li cas ntawm qhov ntev thiab lub sijhawm no yuav pab tau rau kev tsim cov khoom siv yav tom ntej.
Cov hlau nplaum twb siv rau kev khaws cov ntaub ntawv lawm, tab sis cov kws tshawb fawb tam sim no tab tom nrhiav txoj hauv kev los siv nws ntxiv. Piv txwv li, cov kev taw qhia hlau nplaum ntawm lub vortex core thiab thaj chaw ntawm micromagnet tej zaum yuav siv tau los encode cov ntaub ntawv hauv daim ntawv ntawm 0s thiab 1s.
Cov kws tshawb nrhiav tam sim no tab tom tsom mus rau kev rov ua txoj haujlwm no nrog cov khoom siv anti-ferromagnetic, qhov twg cov nyhuv ntawm cov sijhawm sib nqus ib leeg raug tshem tawm. Cov no muaj kev cia siab thaum nws los txog rau kev suav lej - hauv kev xav, cov khoom siv anti-ferromagnetic tuaj yeem siv los ua cov khoom siv uas xav tau lub zog me me thiab tseem ruaj khov txawm tias thaum lub zog poob - tab sis nyuaj dua los tshawb nrhiav vim tias cov cim uas lawv tsim tawm yuav qaug zog dua.
Txawm hais tias muaj qhov teeb meem ntawd los, Folven tseem muaj kev cia siab. "Peb tau ua tiav thawj qhov kev sim los ntawm kev qhia tias peb tuaj yeem ua cov qauv thiab saib lawv nrog X-rays," nws hais. "Kauj ruam tom ntej yuav yog saib seb peb puas tuaj yeem ua cov qauv zoo txaus kom tau txais cov teeb liab txaus los ntawm cov khoom siv anti-ferromagnetic."
Lub sijhawm tshaj tawm: Tsib Hlis-10-2021