https://doi.org/10.1140/epjb/e2006-00245-3
Charge and spin currents tunnelling through a toroidal carbon nanotube side-coupled with a quantum dot
1
CCAST (World Laboratory), P.O. Box 8730, Beijing, 100080, P.R. China
2
Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China
3
Department of Physics, Beijing Institute of Technology, Beijing, 100081, P.R. China
Corresponding author: a zhaohonk@yahoo.com
Received:
25
March
2006
Published online:
21
June
2006
We have investigated the mesoscopic transport through the system
with a quantum dot (QD) side-coupled to a toroidal carbon nanotube
(TCN) in the presence of spin-flip effect. The coupled QD
contributes to the mesoscopic transport significantly through
adjusting the gate voltage and Zeeman field applied to the QD.
The compound TCN-QD microstructure is related to the separate
subsystems, the applied external magnetic fields, as well as the
combination of subsystems. The spin current component Izs is
independent on time, while the spin current components Ixs and
Iys evolve with time sinusoidally. The rotating magnetic field
induces novel levels due to the spin splitting and photon
absorption procedures. The suppression and enhancement of resonant
peaks, and semiconductor-metal phase transition are observed by
studying the differential conductance through tuning the
source-drain bias and photon energy. The magnetic flux induces
Aharonov-Bohm oscillation, and it controls the tunnelling behavior
due to adjusting the flux. The Fano type of multi-resonant
behaviors are displayed in the conductance structures by
adjusting the gate voltage Vg and the Zeeman field
applied to the QD.
PACS: 85.35.-p – Nanoelectronic devices / 73.23.-b – Electronic transport in mesoscopic systems / 72.25.Mk – Spin transport through interfaces / 73.21.La – Quantum dots
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2006