Impact of tunnel-barrier strength on magnetoresistance in carbon nanotubes
Journal article, 2016
We investigate magnetoresistance in spin valves involving CoPd-contacted carbon nanotubes. Both the temperature and bias-voltage dependence clearly indicate tunneling magnetoresistance as the origin. We show that this effect is significantly affected by the tunnel-barrier strength, which appears to be one reason for the variation between devices previously detected in similar structures. Modeling the data by means of the scattering matrix approach, we find a nontrivial dependence of the magnetoresistance on the barrier strength. Furthermore, an analysis of the spin precession observed in a nonlocal Hanle measurement yields a spin lifetime of tau_s=1.1 ns, a value comparable with those found in silicon- or graphene-based spin-valve devices.
Author
Caitlin Morgan
Jülich Research Centre
JARA - Fundamentals of Future Information Technologies
Maciej Misiorny
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
D. Metten
University of Strasbourg
Jülich Research Centre
JARA - Fundamentals of Future Information Technologies
Sebastian Heedt
Jülich Research Centre
JARA - Fundamentals of Future Information Technologies
Thomas Schäpers
Jülich Research Centre
JARA - Fundamentals of Future Information Technologies
Claus M. Schneider
University of Duisburg-Essen
JARA - Fundamentals of Future Information Technologies
Jülich Research Centre
Carola Meyer
Osnabrück University
Jülich Research Centre
JARA - Fundamentals of Future Information Technologies
Physical Review Applied
2331-7019 (eISSN)
Vol. 5 5 054010- 054010Areas of Advance
Nanoscience and Nanotechnology
Subject Categories (SSIF 2011)
Physical Sciences
Condensed Matter Physics
DOI
10.1103/PhysRevApplied.5.054010