عنوان :
مدل هايزنبرگ بر روي شبكه ي لانه زنبوري
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك
صفحه شمار :
هفت،161ص.: مصور
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
فرهاد شهبازي
توصيفگر ها :
ناكامي مغناطيسي , مايع اسپيني , نظم جفتي , نظم بلوكي
تاريخ نمايه سازي :
27/1/91
كد ايرانداك :
ID419 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Heisenberg Model on Honeycomb Lattice Hamid Mosadeq hamid mosadegh@gmail com January 30 2012 Department of Physics Isfahan University of Technology Isfahan 84156 83111 IranFarhad Shahbazi supervisor shahbazi@cc iut ac irAkbar Jafari advisor akbar jafari@gmail comAbstractIn this thesis we study S 1 2 Heisenberg model on honeycomb lattice with first and secondneighbor anti ferromagnetic exchange interactions J1 J2 model by Variational MonteCarlo VMC Exact Diagonalization ED and Bond Operator BO methods First using VMCmethod the stability of Neel order against the frustrating second neighbor interaction J2 isinvestigated We find that the ground state of model remains Neel ordered up to J2 0 2 Beyond this value the ground state becomes classically disordered and VMC calculations areinvalid Exact diagonalization in both the Sz 0 and Nearest Neighbor Valence Bond NNVB bases provides a body of evidence in favor of Plaquette valence bond ordering for 0 2 J2 0 3 This state undergoes a transition to the staggered dimerized state at J2 0 35 The BOcalculations also support the ED results except that this according to this method the Neel toPlaquette transition occurs at J2 0 08 Key Words Heisenberg model Frustration Spin liquid staggered dimerized order plaquette order Department of Physics Isfahan University of Technology Isfahan 84156 83111 Iran Department of Physics Sharif University of Technology Tehran 11155 9161 Iran
استاد راهنما :
فرهاد شهبازي
