Using the density functional theory and the nonequilibrium Green＇s function method, we studied the finite-bias quan- tum transport in a Cr/graphene/Cr magnetotunnel junction （MTJ） constructed by a single graphene l...Using the density functional theory and the nonequilibrium Green＇s function method, we studied the finite-bias quan- tum transport in a Cr/graphene/Cr magnetotunnel junction （MTJ） constructed by a single graphene layer sandwiched be- tween two semi-infinite Cr（111 ） electrodes. We found that the tunneling magnetoresistance （TMR） ratio in this MTJ reached 108%, which is close to that of a perfect spin filter. Under an external positive bias, we found that the TMR ratio remained constant at 65%, in contrast to MgO-based MTJs, the TMR ratios of which decrease with increasing bias. These results indicate that the Cr/graphene/Cr MTJ is a promising candidate for spintronics applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.10874143,10974166,and 11574260)the Program for New Century Excellent Talents in University,China(Grant No.NCET-10-0169)+1 种基金the National Innovation Foundation for Graduate,China(Grant No.201310530003)the Computational Support from Shanghai Super-computer Center,China
文摘Using the density functional theory and the nonequilibrium Green＇s function method, we studied the finite-bias quan- tum transport in a Cr/graphene/Cr magnetotunnel junction （MTJ） constructed by a single graphene layer sandwiched be- tween two semi-infinite Cr（111 ） electrodes. We found that the tunneling magnetoresistance （TMR） ratio in this MTJ reached 108%, which is close to that of a perfect spin filter. Under an external positive bias, we found that the TMR ratio remained constant at 65%, in contrast to MgO-based MTJs, the TMR ratios of which decrease with increasing bias. These results indicate that the Cr/graphene/Cr MTJ is a promising candidate for spintronics applications.
