پديد آورنده :
جبلي، هدي السادات
عنوان :
محاسبه ي ابتدا به ساكن انحناي بري و رسانايي ذاتي غير عادي هال در مواد فرومغناطيس با استفاده از توابع وانير بيشينه جايگزيده
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك
صفحه شمار :
[هشت]، 91ص.:مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
جواد هاشمي فر
استاد مشاور :
هادي اكبر زاده
توصيفگر ها :
فاز بري , انحناي بري , برهم كنش اسپين مدار , آهن , كبالت , لايه نازك آهن
تاريخ نمايه سازي :
13/4/89
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
First Principles study of Berry curvature and intrinsic anomalous Hall conductivity in ferromagnetic materials by using Maximally Localized Wannier Functions Hoda Alsadat Jebeli E mail address h jebeli@ph iut ac ir Date of Submission 31 1 2010 Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Dr S Javad Hashemifar Abstract The Hall e ect in ferromagnetic materials in addition to the normal part originating from the Lorentz force contains a supplementary part due to the spin orbit coupling called the anomalous Hall e ect While the normal Hall conductivity is proportional to the applied magnetic eld the anomalous Hall conductivity is found to be proportional to the magnetization and is usually much greater than the normal part In recent years the anomalous Hall conductivity has been explained in the modern language of Berry phase and Berry curvature The Berry phase is a kind of geometry phase being acquired by a wave vector when it moves along a closed path in the phase space The integral of the Berry curvature over the surface enclosed by the closed path is the Berry phase of the corresponding path According to the di erent studies the Berry curvature has sharp and rapid variations in k space therefore in order to converge the required integrals the Berry curvature has to be evaluated over millions of k points in the Brillouin zone leading to expensive computational cost Wannier interpolation technique has been proposed as an e cient approach for solving this problem and obtaining accurate electronic structure on a very dense kmesh In this work we develop appropriate programs for calculating the Berry curvature in any kpoint by using Maximally Localized Wannier Functions Then the intrinsic anomalous Hall conductivity is determined in the frame work of the semiclassical theory of transport We use our programs to calculate the intrinsic anomalous Hall conductivity of bcc Fe and hcp Co in the bulk state and Fe thin lm and compare our results with experimental data Key Words anomalous Hall conductivity Berry phase Berry curvature spin orbit coupling Wannier function Fe Co Fe thin lm
استاد راهنما :
جواد هاشمي فر
استاد مشاور :
هادي اكبر زاده
