Spin-dependent transport and spin transfer torque in a system based on silagraghene nanoribbons

Abstract

We theoretically investigate the spin-dependent transport and spin transfer torque ( S T T ) in a system composed of a silagraphene nanoribbon ( S L N R ) connected to two ferromagnetic ( F M ) leads with arbitrary relative magnetization direction, using the tight-binding model in the nearest neighbor approximation within the framework of the Green function’s technique and Landauer–Butticer formalism. We report numerical calculation results for conductance ( G ), magnetoresistance ( M R ), and spin transfer torque ( S T T ) in the F M / S L N R / F M junction for different strengths of ferromagnetic magnetization. It is found that the G and M R show oscillatory behavior around E F = 0 and more interestingly, the magnitude of the M R reaches up to % 100 , which can be effectively used for sensitive switchings. In addition, it is demonstrated that S T T versus Fermi energy shows noticeable peaks with moving away from Dirac point energy. The results show that the torques as a function of the angle between two magnetic electrodes ( θ ) show a s i n -like behavior and the G − θ curve demonstrates approximately a c o s i n e -like behavior, which is a function of M . Our results can provide valuable theoretical guidance to design future novel spintronic devices. • We report the spin-polarized transport in a system based on silagraphene. • Our system consists of a silagraphene nanoribbon connected to two ferromagnetic electrodes (FM/Silagraphene/FM). • We employ Green function’s technique and Landauer–Butticer formalism. • We consider the conductance, magnetoresistance and spin transfer torque in this system for different strengths of ferromagnetic magnetization. • Our results demonstrate that the G, MR and STT show oscillatory behavior around Dirac point. • We found the n-type impurity is more suitable for dopping the system.