27754

بررسي ترابرد وابسته به اسپين و دره در نانونوارهاي فسفرين و بروفين

كارشناسي ارشد

فيزيك

98-1401

1401/7/2

دكتر ادريس فيض آبادي

فيزيك

در اين تحقيق به مطالعه ي ترابري الكترون در مدل بستگي قوي و با در نظر گرفتن درجات آزادي اسپين در نانو نوارهاي فسفرين و بروفين با استفاده از روش تابع گرين غير تعادلي پرداخته شده است. نانو نوارهاي فسفرين در حضور بر همكنش اسپين مدار رشبا و در عرض ها وطول هاي مختلف بررسي شده اند و ايجاد شكاف در نانونوارهاي پهن براي مشاهده واروني اسپيني كامل در اين ساختارها پيشنهاد شده است. نانونوارهاي بروفين در حضور ميدان مغناطيسي تبادلي بررسي شده اند و نتايج نشان مي دهند كه نانو نوارهاي بروفين تنها در حضور ميدان مغناطيسي تبادلي قادر به توليد جريان قطبيده اسپيني هستند.

1401/11/01

Spin and Valley dependent transport through phosphorene and borophene nanoribbons

9/24/2023 12:00:00 AM

We have investigated the spin-dependent transport through phosphorene and β_12-borophene nanoribbons in a tight-binding frame using the non-equilibrium Green’s function method. Spin-dependent transport in phosphorene nanoribbons is studied in the presence of Rashba spin-orbit (RSOI) interaction which is induced via a perpendicular electric field. The effects of the length and width of armchair phosphorene nanoribbons have been assessed. The results show that the quantum transport in phosphorene nanoribbons with an odd number of atoms in the length is highly suppressed due to destructive quantum interferences. Considering the injected electrons fully polarized, the spin-flip effect can be detected in armchair phosphorene nanoribbons in the presence of RSOI. However, this phenomenon deteriorates gradually as the width of the nanoribbon increases. As a solution, creating split(s) in wide armchair phosphorene nanoribbons has been suggested. A split is a row of atoms that are removed from the structure. It changes the quantum interference pattern and increases the scattering. If the splits are created in effective positions, they can cause effective spin-flip in armchair phosphorene nanoribbons. Spin polarization through β_12-zigzag borophene nanoribbons with different widths has also been investigated. We have increased the strength of the exchange field gradually from 0 to 0.05 eV. Our results show that for observing spin polarization through β_12-zigzag borophene nanoribbons with different widths, the strength of the exchange field must be higher than 0.001 eV. By increasing the exchange field and obtaining high transmission probability, ZBNRs are able to generate a pure spin current which can be exploited in designing spintronic devices.

نانونوار فسفرين , نانونوار بروفين , بر همكنش اسپين مدار رشبا , قطبش اسپيني , تابع گرين غيرتعادلي

phosphorene nanoribbons , borophene nanoribbons , Rashba spin orbit interaction , spin polarization , non-equilibrium Green’s function

Faezeh Shabani

Edris Faizabadi