Share Email Print

Proceedings Paper

Spin relaxation in spin light-emitting diodes: effects of magnetic field and temperature
Author(s): Henning Höpfner; Carola Fritsche; Arne Ludwig; Astrid Ludwig; Frank Stromberg; Heiko Wende; Werner Keune; Dirk Reuter; Andreas D. Wieck; Nils C. Gerhardt; Martin R. Hofmann
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

We report experimental results on the electron spin relaxation length during vertical transport in spin lightemitting diodes (LEDs). Our devices are GaAs based LEDs with InAs quantum dots in the active region, an MgO tunnel barrier and an Fe/Tb multilayer spin injector with perpendicular magnetic anisotropy, i.e. remanent out-of-plane magnetization, enabling efficient electrical spin injection in magnetic remanence. Additionally, our devices can be operated at room temperature. A series of samples with different injection path lengths allows us to experimentally determine the spin relaxation length in our devices. In combination with operation in magnetic remanence, we are able to determine the spin relaxation length without the influence of external magnetic fields and at room temperature and find it to be 27 nm. Applying an additional external magnetic field, we find that at a field strength of 2 T, this relaxation length almost doubles, which is in good agreement with spin relaxation times in GaAs. Temperature control of our samples allows us to measure the temperature dependence of the spin relaxation length. At 200 K, the spin relaxation length doubles to 50 nm and reaches 80 nm at 30 K, in good agreement with theoretic calculations. Our results show that polarization values obtained with spin-LEDs inside strong magnetic fields and at low temperatures are not comparable to those in remanence and at room temperature. However, the transfer of efficient spintronic devices to such applicationenabling settings is absolutely necessary and will be a major challenge considering the enormous differences in spin relaxation.

Paper Details

Date Published: 14 March 2013
PDF: 7 pages
Proc. SPIE 8623, Ultrafast Phenomena and Nanophotonics XVII, 86230A (14 March 2013); doi: 10.1117/12.2001511
Show Author Affiliations
Henning Höpfner, Ruhr-Univ. Bochum (Germany)
Carola Fritsche, Ruhr-Univ. Bochum (Germany)
Arne Ludwig, Ruhr-Univ. Bochum (Germany)
Astrid Ludwig, Ruhr-Univ. Bochum (Germany)
Frank Stromberg, Univ. Duisburg-Essen (Germany)
Heiko Wende, Univ. Duisburg-Essen (Germany)
Werner Keune, Univ. Duisburg-Essen (Germany)
Dirk Reuter, Univ. Paderborn (Germany)
Andreas D. Wieck, Ruhr-Univ. Bochum (Germany)
Nils C. Gerhardt, Ruhr-Univ. Bochum (Germany)
Martin R. Hofmann, Ruhr-Univ. Bochum (Germany)

Published in SPIE Proceedings Vol. 8623:
Ultrafast Phenomena and Nanophotonics XVII
Markus Betz; Abdulhakem Y. Elezzabi; Jin-Joo Song; Kong-Thon Tsen, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?