عنوان
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مطالعه ی اثر تغییر در تعداد همسایه های جفت شده در آمار مقدار ویژه های هامیلتونی
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نوع پژوهش
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پایان نامه
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کلیدواژهها
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Anderson localization, delocalized-localized phase transition, long-range hopping amplitude, statistics of level spacing
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چکیده
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Anderson phase transition between delocalized and delocalized phases happens only in 3 dimension. It means that the lower critical dimention for the Anderson model is 3. In contrast for one and two dimensional models with even infinitesimally disorder there will not be any phase transitions and all states become localized. On the other hand, we know that by increasing the number of neighboring sites we are actually increasing the dimentions or vice versa. Thus, in this thesis, we consider a one-dimensional Anderson model with random uncorrelated on-site energies and increase the number of coupled neighbores and in this way we want to find the relation between the localization properties of the considered system and the number of neighbores. To characterize the Anderson localization we consider statistics of level spacing. We found that By increasing the number of neighbores the statistics changes from delocalized phase to localized phase.
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پژوهشگران
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محمد پورانوری (استاد راهنما)، اسرا قاسم نعیمه البهادیلی (دانشجو)
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