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TT: Tiefe Temperaturen
TT 15: Transport: Nanoelectronics II - Spintronics and Magnetotransport - Part 1
TT 15.1: Hauptvortrag
Dienstag, 28. März 2006, 12:30–13:00, HSZ 02
Electric field control of spin transport in carbon nanotubes — •Takis Kontos1,2, Sangeeta Sahoo1, Juerg Furer1, Christian Hoffmann1,3, Matthias Gräber1, Audrey Cottet1,4, and Christian Schönenberger1 — 1Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056, Basel, Switzerland — 2LPA, ENS, 24, rue Lhomond, 75231 Paris Cedex 05, France — 3CRTBT, Grenoble, France — 4LPS, Université Paris-Sud, 91405, Orsay, France
Spintronics is an approach to electronics in which the spin of the electron is exploited to control the electric resistance R of devices. One basic building block is the spin-valve, which is formed if two ferromagnetic electrodes are separated by a thin tunnelling barrier. In such devices, R depends on the orientation of the magnetization of the electrodes. It is usually larger in the antiparallel than in the parallel configuration. The relative difference of R, the so-called magneto-resistance (MR), is then positive.
The MR may become anomalous (negative), if the transmission probability of electrons through the device is spin or energy dependent. This offers a route to the realization of gate-tunable MR devices. Using carbon nanotubes with a new type of ferromagnetic contacts [1] (based on the Pd1−xNix alloy), we demonstrate a spin field-effect transistor (Spin-FET), in which the amplitude and the sign of the MR are tunable with the gate voltage in a predictable manner [2].
[1] S. Sahoo, T.Kontos, C. Schönenberger and C. Sürgers , Appl. Phys. Lett. 86, 112109 (2005)
[2] S. Sahoo, T. Kontos, J. Furer, C. Hoffmann, M. Gräber, A. Cottet and C. Schönenberger Nature Phys. 2, 99 (2005)