12252

11223

كارشناسي ارشد

ماده چگال

اصفهان: دانشگاه صنعتي اصفهان، دانشكده فيزيك

1395

نه، 87ص.: مصور، جدول، نمودار

ص. ع. به فارسي و انگليسي

1395/12/08

كتابنامه

فيزيك

فيزيك

ID11223

Abstract The two dimensional graphene structure is composed of the isotropichoneycomb lattice of carbon atoms The graphene structure has several speci celectronic properties For instance there are no gaps in energy bands of theFermi level and electrons behave similar to the Dirac fermions In this struc ture anisotropy can be created by electrochemical pressure exertion so thatthe geometry and the parameters of lattice change In this thesis the e ectsof anisotropy in one direction in the electronic nano structure of graphene us ing Hubbard model known as tight binding method are studied Therefore then states explaining the electronic properties are considered and the electronicbands of n states are compared with the electronic bands of isotropy honeycomblattice in graphene Consequently the spectral function and density states arestudied for both states of the honeycomb lattice of graphene According to theresults of the study the gap in electronic bands will be created in the Fermi levelwith pressure or tension exertion In the next step strongly correlated materi als due to the nding high temperature superconductors and the metal insulatorphase transition in these metals are studied One of the simplest models to studythese metals is the Hubbard model In this model in addition to the kinetic en ergy of electrons the interaction between electrons are considered and the largeinteraction and half lling state in this model using dynamical mean eld theoryare studied Keywords electronic bands tight binding anisotropy Hubbard model dynami cal mean eld theory

پيمان صاحب سرا

فرهاد فضيله

ممتحن داخلي1: وحيد سالاري; ممتحن داخلي2: حجت قلي زاده