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Injection of spin polarized electrons in InAs quantum dots

Published online by Cambridge University Press:  31 January 2011

Andreas Russ
Affiliation:
[email protected], SUNY Buffalo, Physics, Buffalo, New York, United States
Mesut Yasar
Affiliation:
[email protected], SUNY Buffalo, Physics, Buffalo, New York, United States
Athos Petrou
Affiliation:
George Kioseoglou
Affiliation:
[email protected], University of Crete, Heraclion, Greece
Connie Li
Affiliation:
[email protected], Naval Research Laboratory, Washington, DC, District of Columbia, United States
Aubrey Hanbicki
Affiliation:
[email protected], Naval Research Laboratory, Washington, DC, District of Columbia, United States
Berend Jonker
Affiliation:
[email protected], Naval Research Laboratory, Washington, DC, District of Columbia, United States
Marek Korkusinski
Affiliation:
[email protected], National Research Council, Institute for Microstructural Sciences, Ottawa, Canada
Pawel Hawrylak
Affiliation:
[email protected], National Research Council, Institute for Microstructural Sciences, Ottawa, Canada
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Abstract

We present the results of an electrical injection study of spin polarized electrons from ferromagnetic Fe contacts into electronic shells of self-assembled InAs quantum dots (QDs) incorporated in GaAs/AlGaAs spin LED structures. The circular polarization of the emitted light was measured as function of current and magnetic field. The polarization of the EL spectra exhibits strong maxima at energies that do not coincide with the electroluminescence (EL) intensity peaks. The magnetic field dependence of the polarization maxima is consistent with spin injection from the ferromagnetic Fe contacts. The experimental results are compared with calculated emission spectra from multi-exciton complexes (N = 2 and N = 6) as function of electron spin polarization. The energies of the EL features as well as their polarization characteristics are understood in terms of energy shifts due to exchange interactions between spin-down electrons occupying adjacent shells.

Keywords

Type
Research Article
Copyright
Copyright © Materials Research Society 2010

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References

[1] Sachrajda, A., Hawrylak, P., and Ciorga, M., “Nano-spintronics with lateral quantum dots,” in Transport in Quantum Dots, Bird, J., Ed.: Kluwer, 2003.Google Scholar
[2] Hawrylak, P. and Korkusinski, M., “Electronic and optical properties of self-assembled quantum dots,” in Single quantum dots Fundamentals, Applications, and New Concept, Topics in Applied Physics. vol. 90, Michler, P., Ed.: Springer-Verlag, 2003.Google Scholar
[3] Kato, Y., Myers, R. C., Gossard, A. C., and Awschalom, D. D., “Coherent spin manipulation without magnetic fields in strained semiconductors,” Nature, vol. 427, pp. 5053, Jan 1 2004.Google Scholar
[4] Petta, J. R., Johnson, A. C., Taylor, J. M., Laird, E. A., Yacoby, A., Lukin, M. D., Marcus, C. M., Hanson, M. P., and Gossard, A. C., “Coherent manipulation of coupled electron spins in semiconductor quantum dots,” Science, vol. 309, pp. 21802184, Sep 30 2005.Google Scholar
[5] Paillard, M., Marie, X., Renucci, P., Amand, T., Jbeli, A., and Gerard, J. M., “Spin relaxation quenching in semiconductor quantum dots,” Physical Review Letters, vol. 86, pp. 16341637, Feb 2001.Google Scholar
[6] Jonker, B. T., Park, Y. D., Bennett, B. R., Cheong, H. D., Kioseoglou, G., and Petrou, A., “Robust electrical spin injection into a semiconductor heterostructure,” Physical Review B, vol. 62, pp. 81808183, Sep 15 2000.Google Scholar
[7] Hanbicki, A. T., Jonker, B. T., Itskos, G., Kioseoglou, G., and Petrou, A., “Efficient electrical spin injection from a magnetic metal/tunnel barrier contact into a semiconductor,” Applied Physics Letters, vol. 80, pp. 12401242, Feb 18 2002.Google Scholar
[8] Hanbicki, A. T., Erve, O. M. J. van 't, Magno, R., Kioseoglou, G., Li, C. H., Jonker, B. T., Itskos, G., Mallory, R., Yasar, M., and Petrou, A., “Analysis of the transport process providing spin injection through an Fe/AlGaAs Schottky barrier,” Applied Physics Letters, vol. 82, pp. 40924094, Jun 2003.Google Scholar
[9] Fiederling, R., Keim, M., Reuscher, G., Ossau, W., Schmidt, G., Waag, A., and Molenkamp, L. W., “Injection and detection of a spin-polarized current in a light-emitting diode,” Nature, vol. 402, pp. 787790, Dec 16 1999.Google Scholar
[10] Chye, Y., White, M. E., Johnston-Halperin, E., Gerardot, B. D., Awschalom, D. D., and Petroff, P. M., “Spin injection from (Ga,Mn)As into InAs quantum dots,” Physical Review B, vol. 66, p. 4, Nov 2002.Google Scholar
[11] Loffler, W., Trondle, D., Fallert, J., Kalt, H., Litvinov, D., Gerthsen, D., LupacaSchomber, J., Passow, T., Daniel, B., Kvietkova, J., Grun, M., Klingshim, C., and Hetterich, M., “Electrical spin injection from ZnMnSe into InGaAs quantum wells and quantum dots,” Applied Physics Letters, vol. 88, p. 3, Feb 2006.Google Scholar
[12] Itskos, G., Harbord, E., Clowes, S. K., Clarke, E., Cohen, L. F., Murray, R., Dorpe, P. Van, and Roy, W. Van, “Oblique Hanle measurements of InAs/GaAs quantum dot spin-light emitting diodes,” Applied Physics Letters, vol. 88, p. 3, Jan 2006.Google Scholar
[13] Li, C. H., Kioseoglou, G., Erve, O. M. J. van 't, Ware, M. E., Gammon, D., Stroud, R. M., Jonker, B. T., Mallory, R., Yasar, M., and Petrou, A., “Electrical spin pumping of quantum dots at room temperature,” Applied Physics Letters, vol. 86, Mar 2005.Google Scholar
[14] Korkusinski, M. and Hawrylak, P., “Optical signatures of spin polarization of carriers in quantum dots,” Physical Review Letters, vol. 101, pp. 02720510272054, Jul 11 2008.Google Scholar
[15] Wasilewski, Z. R., Fafard, S., and McCaffrey, J. P., “Size and shape engineering of vertically stacked self-assembled quantum dots,” Journal of Crystal Growth, vol. 202, pp. 11311135, May 1999.Google Scholar
[16] Joyce, P. B., Krzyzewski, T. J., Bell, G. R., Jones, T. S., Malik, S., Childs, D., and Murray, R., “Effect of growth rate on the size, composition, and optical properties of InAs/GaAs quantum dots grown by molecular-beam epitaxy,” Physical Review B, vol. 62, pp. 1089110895, Oct 15 2000.Google Scholar
[17] Raymond, S., Studenikin, S., Sachrajda, A., Wasilewski, Z., Cheng, S. J., Sheng, W., Hawrylak, P., Babinski, A., Potemski, M., Ortner, G., and Bayer, M., “Excitonic energy shell structure of self-assembled InGaAs/GaAs quantum dots,” Physical Review Letters, vol. 92, May 2004.Google Scholar
[18] Narvaez, G. A., Bester, G., and Zunger, A., “Carrier relaxation mechanisms in self-assembled (In,Ga)As/GaAs quantum dots: Efficient P -> S Auger relaxation of electrons,” Physical Review B, vol. 74, p. 7, Aug 2006.+S+Auger+relaxation+of+electrons,”+Physical+Review+B,+vol.+74,+p.+7,+Aug+2006.>Google Scholar
[19] Li, C. H., Kioseoglou, G., Hanbicki, A. T., Goswami, R., Hellberg, C. S., Jonker, B. T., Yasar, M., and Petrou, A., “Electrical spin injection into the InAs/GaAs wetting layer,” Applied Physics Letters, vol. 91, pp. 26250412625043, Dec 24 2007.Google Scholar
[20] Bayer, M., Stern, O., Hawrylak, P., Fafard, S., and Forchel, A., “Hidden symmetries in the energy levels of excitonic ‘artificial atoms’,” Nature, vol. 405, pp. 923926, Jun 2000.Google Scholar
[21] Sheng, W. D. and Hawrylak, P., “Spin polarization in self-assembled quantum dots,” Physical Review B, vol. 73, pp. 12533111253314, Mar 2006.Google Scholar
[22] Cheng, S. J., Sheng, W. D., and Hawrylak, P., “Theory of excitonic artificial atoms: InGaAs/GaAs quantum dots in strong magnetic fields,” Physical Review B, vol. 68, pp. 235330123533010, Dec 2003.Google Scholar