arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 0811.2960cond-mat.mes-hall
收藏

通过载流子漂移控制石墨烯中的自旋注入效率

Controlling the efficiency of spin injection into graphene by carrier drift

C. Józsa, M. Popinciuc, N. Tombros, H. T. Jonkman, B. J. van Wees

摘要:

从铁磁金属到石墨烯的电自旋注入受到两种材料之间的阻抗失配的阻碍。这个问题可以通过在界面处引入薄的隧道势垒来减少。我们在钴/氧化铝/石墨烯结构中进行了室温非局域自旋阀测量,注入效率高达25%,其中通过氧化物中相对透明的针孔实现电接触。通过在注入器电极上施加DC电流偏置,该值进一步提高到43%,这导致载流子漂移远离接触。反向偏置将AC自旋阀信号减小到零或负值。我们引入了一个模型,定量预测在这种情况下,在石墨烯中的自旋积累的行为,显示出良好的协议与我们的测量。

英文摘要:

Electrical spin injection from ferromagnetic metals into graphene is hindered by the impedance mismatch between the two materials. This problem can be reduced by the introduction of a thin tunnel barrier at the interface. We present room temperature non-local spin valve measurements in cobalt/aluminum-oxide/graphene structures with an injection efficiency as high as 25%, where electrical contact is achieved through relatively transparent pinholes in the oxide. This value is further enhanced to 43% by applying a DC current bias on the injector electrodes, that causes carrier drift away from the contact. A reverse bias reduces the AC spin valve signal to zero or negative values. We introduce a model that quantitatively predicts the behavior of the spin accumulation in the graphene under such circumstances, showing a good agreement with our measurements.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑