Strain Effect On Electronic Structures And Transport Properties Of ?-T₃ Nanoribbons

In this thesis,under the framework of the mean field Hubbard model,we the-oretically study the spin-dependent electronic structure and transport properties of zigzag-edge?-T₃ nanoribbons with and without uniaxial strain.Then,using the similar method,the electronic structure of armchair?-T₃ nanoribbons under applying uniaxial strains of different directions and different strengths for different coupling strengths?are explored.The first two chapters focus on the relationship between the?-T₃ model and graphene.Next,some important research works and the excellent physical properties of two-dimensional?-T₃ lattices and its nanoribbons are systematically described.Then the non-equilibrium Green's function and equilibrium Green's function are introduced in mesoscopic transport theoryIn Chapter 3,we studied the influence of electron interaction on the elec-tronic structure and electron transport properties of the zigzag?-T₃ nanoribbons.The regulation of strain on electronic structure is also studied?It is found that electronic structure of the zigzag?-T₃ nanoribbons can be effectively manipulated by the?,uniaxial strain and Coulomb interaction.The flat band at the Fermi energy is split and moves in the opposite direction,and the distance between the flat bands decreases with the increase of the?.In addition,ground state of anti-ferromagnetic to ferromagnetic transition occurs when?increases from 0.8 to 1,leading to a semiconductor to metallic transition.The fourth chapter explores the electronic structure and conductance of arm-chair?-T₃ nanoribbon by applying uniaxial strains along directions of Zigzag and Armchair chains under different?.The energy gap can be effectively adjusted by parameters?and uniaxial strain,and apply the strain along the armchair chain,the value of?has almost no effect on the energy gap under small strain.The find-ings here may be of importance in the band gap engineering and electromechanical applications of?-T₃ nanoribbon-based devices.In chapter five,a summary of the work and a outlook of this topic are given.