Size effect of spin-polarized transport in FM/Single-walled carbon nanotube/FM junctions

作者：Liu Hong^*

来源：Physics Letters A, 2012, 376(45): 3295-3300.

DOI：10.1016/j.physleta.2012.09.048

• Single-walled carbon nanotube
• Spin-polarized transport
• TMR effect

We investigated theoretically in detail the size effect of spin-polarized transport in FM/Single-walled carbon nanotube/FM junctions (FM/SWCNT/FM) consisting of the achiral types of tubes: armchair tubes and zigzag tubes. The results show that the spin-polarized transport has different oscillation behaviors with the junction's size in these two junctions. And the effect of tunnel magnetoresistance (TMR) in zigzag tube is stronger than that in armchair tubes. For all zigzag tubes when the size exceeds a limit the size effect on TMR disappears and TMR value reaches one maximum 20%. Furthermore, for each family of zigzag tubes, this limit of size increases with increasing tube's radius. For short zigzag tubes the TMR can be negative at some special sizes. And the negative TMR value can reach -12% at the angle pi. Finally, except for the zero angel, the obtained results show that for all zigzag tubes the extremum of TMR is at the angle pi. For all armchair tubes, the TMR value has one oscillation of small amplitude with the increase of angle and it has two extrema: the maximum at pi/2 and the minimum at pi, respectively.

• 出版日期2012-10-1
• 单位南京师范大学