Ukrainian Journal of Physical Optics

Spin polarization of dilute magnetic semiconductors under optical excitation of impurity levels
¹Gorley P.M., ¹Mysliuk O.M., ²Vieira M., ^1,3Horley P.P., ⁴Dugaev V.K., ⁵Barnas J.

¹Department of Electronics and Energy Engineering, Yuri Fedkovych Chernivtsi National University, 2 Kotsyubynsky St., 58012 Chernivtsi, Ukraine
²Dept. de Engenharia Electrotécnica, ISEL, Rua Conselheiro Emídio Navarro, 1950-062 Lisbon, Portugal
³CFIF, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
⁴Department of Mathematics and Applied Physics, Rzeszów University of Technology, 6 Powstanców Warszawy St., 35-959 Rzeszów, Poland
⁵Institute of Molecular Physics, Polish Academy of Sciences, 60-179 Poznan, Poland

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We use the method based on kinetic equations to analyze the influence of intensity and polarization of incident light, concentration of impurities with unfilled 3d or 4f shells and long-term relaxation times of conduction electrons and magnetic ions upon the degree of spin polarization. In case of spatially inhomogeneous stationary states, the distribution of band electrons is shown to oscillate in space, with a transition to spatially homogeneous distribution for infinitely thick sample. It is also demonstrated that the maximum spin polarization degree h_e for the band electrons can be reached for the thickness of semiconductor film comparable to the diffusion length for the minority carriers.

Keywords: optical excitation, spin polarization, spintronics, diluted magnetic semi-conductors

PACS: 72.25.Fe, 72.25.Rb, 72.25.-b, 78.20.Bh, 78.40.Fy
UDC: 535.568
Ukr. J. Phys. Opt. 9 60-71
doi: 10.3116/16091833/9/1/60/2008
Received: 18.12.2007

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(c) Ukrainian Journal of Physical Optics