Theoretical studies of spin-dependent electrical transport through carbon nanotbes

Details Theoretical studies of spin-dependent electrical transport through carbon nanotbes Theoretical studies of spin-dependent electrical transport through carbon nanotbes

2006-07-14

arxiv.org/abs/cond-mat/0607363v1

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

15 pages, 6 figures (to apppear in Semicond. Sci. Technol.)

Scientific paper

10.1088/0268-1242/21/11/S12

Spin-dependent coherent quantum transport through carbon nanotubes (CNT) is studied theoretically within a tight-binding model and the Green's function partitioning technique. End-contacted metal/nanotube/metal systems are modelled and next studied in the magnetic context, i.e. either with ferromagnetic electrodes or at external magnetic fields. The former case shows that quite a substantial giant magnetoresistance (GMR) effect occurs ($\pm 20%$) for disorder-free CNTs. Anderson-disorder averaged GMR, in turn, is positive and reduced down to several percent in the vicinity of the charge neutrality point. At parallel magnetic fields, characteristic Aharonov-Bohm-type oscillations are revealed with pronounced features due to a combined effect of: length-to-perimeter ratio, unintentional electrode-induced doping, Zeeman splitting, and energy-level broadening. In particular, a CNT is predicted to lose its ability to serve as a magneto-electrical switch when its length and perimeter become comparable. In case of perpendicular geometry, there are conductance oscillations approaching asymptotically the upper theoretical limit to the conductance, $4 e^2/h$. Moreover in the ballistic transport regime, initially the conductance increases only slightly with the magnetic field or remains nearly constant because spin up- and spin down-contributions to the total magnetoresistance partially compensate each other.

Affiliated with

Also associated with

No associations

Rating

Theoretical studies of spin-dependent electrical transport through carbon nanotbes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Theoretical studies of spin-dependent electrical transport through carbon nanotbes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Theoretical studies of spin-dependent electrical transport through carbon nanotbes will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-96932