چكيده به لاتين
Over the past decade, a lot of research on two-dimensional materials such as Graphene, Silicene, Molybdenum disulfide (MoS2) and similar compounds have been studied in condensed matter physics. One of the most famous family members of transition metal dichalcogenides that has special properties as a semiconductor, is Molybdenum disulfide. Molybdenum disulfide is formed honeycomb structure. Specific feature of Molybdenum disulfide can be changed from indirect band gap (1.2 eV) in Bulk to direct band gap in monolayer (1.86 eV). In this thesis, we will calculate the eleven-band spinless orthogonal by tight-binding model. Then, the surface Green’s function of left and right leads are calculated by suing the Lopez-Sancho’s algorithm. Finally, we consider zigzag and armchair nanoribbon of MoS2 and study its spin and electron-dependent conductance in the presence of impurity, transverse electric field and exchange field with parallel (anti-parallel) configurations. We show threshold voltage can be changed in the current-voltage curve by vacancy at zigzag MoS2 nanoribbon. Then, under applying the transverse electric field, we demonstrate the ribbon behaves as a prefect spin up (down) filter if and only if the exchnge field on edge are present. Finally, by anti-parallel configurations of exchange magnetic fields generated by ferromagnetic at armchair MoS2 nanoribbon edges and applying transverse electric field, we show by changing direction of transverse electric field, the ribbon acts as a spin inverter.
Keywords: two-dimensional material - Molybdenum disulfide - transition metal dichalcogenide - direct band gap - Green’s function - transverse electric field - exchange field- perefect spin filtering
