https://doi.org/10.1140/epjb/e2005-00324-y
Spin-flip mesoscopic transport through a quantum dot coupled to carbon nanotube terminals
1
CCAST (World Laboratory), P.O. Box 8730, Beijing 100080, P.R. China
2
Department of Physics, Beijing Institute of Technology,
Beijing 100081, P.R. China
Corresponding author: a zhaohonk@yahoo.com
Received:
8
April
2005
Revised:
30
May
2005
Published online:
11
October
2005
We investigate mesoscopic transport through a system that consists of a central quantum dot (QD) and two single-wall
carbon nanotube (SWCN) leads in the presence of a rotating
magnetic field. The spin-flip effect is induced by the rotating
magnetic field, and the tunnelling current is sensitively related
to the spin-flip effect. We present the calculations of charge
and spin current components to show the intimate relations to the
SWCN leads. Zeeman effect is important when the applied magnetic
field is strong enough. The current characteristics are quite
different when the source-drain bias is zero (eV=0) and nonzero
(). The asymmetric peak and valley of spin current versus
gate voltage exhibit Fano resonance. Multi-resonant peaks of spin
current versus photon energy
reflect the structure
of CN quantum wires, as well as the resonant photon absorption and
emission effect. The matching-mismatching of channels in the CN
leads and QD results in novel spin current structure by tuning the
frequency.
PACS: 73.40.-c – Electronic transport in interface structures / 73.63.Fg – Nanotubes / 73.61.Wp – Fullerenes and related materials / 73.22.-f – Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005