Berlin 2005 – scientific programme
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HL: Halbleiterphysik
HL 21: Spintronik III
HL 21.3: Talk
Saturday, March 5, 2005, 11:15–11:30, TU P164
Diluted magnetic semiconductor resonant tunneling diodes as spin polarized current detectors. — •Anatoliy Slobodskyy1, Charles Gould1, Taras Slobodskyy1, Peter Grabs1, David Sánchez2, Georg Schmidt1, and Laurens Molenkamp1 — 1Physikalisches Institut der Universität Würzburg EP3, Am Hubland, D-97074 Würzburg, Germany — 2Département de Physique Théorique, Université de Genève, CH-1211 Genève 4, Switzerland
We previously demonstrated spin dependent transport on all-II-VI resonant tunneling diodes (RTD) with a magnetic quantum well [1]. We now present new results on these structures, showing that they can be operated as spin detection devices. Current voltage characteristics of the samples were measured in magnetic fields (B) up to 16 T and temperature down to 40 mK. At intermediate fields, the B=0 spin degenerate resonance splits into spin-up and spin-down components following the Giant Zeeman splitting of the well material. At higher magnetic fields, a strong change in the relative amplitude of the spin-split resonances is observed. This results from an interplay between the Giant Zeeman splitting in the quantum well and normal Zeeman splitting in the injector. The Zeeman splitting of the bottom of the conduction band in the injector polarizes the current injected into the RTD, and this polarization is detected by the spin selectivity of the quantum well states. A straight forward model correctly describing the voltage, temperature, and magnetic field dependence of the device is presented.
[1] A. Slobodskyy, C. Gould, T. Slobodskyy, C.R. Becker, G. Schmidt, and L.W. Molenkamp, Phys. Rev. Lett. 90, 246601 (2003)