▎ 摘　　要

The aim of this study is to gain a deeper insight into the impact of geometrical dimensions (aspect ratio) and current direction (zigzag vs armchair) on transport characteristics It is found that there is a pronounced dependence of the giant magnetoresistance (in setups with 2 ferromagnetic electrodes), as well as the spin polarization of current (in the case of one paramagnetic and one ferromagnetic electrode) on the bias and gate voltages, meaning a possible electrical control of magnetic properties of these quantities