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arXiv · 1210.3302

Optical orientation of nuclei in nitrogen alloys GaAsN at room temperature

V. K. Kalevich·M. M. Afanasiev·A. Yu. Shiryaev·A. Yu. Egorov
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Abstract

The intensity and the giant circular polarization of edge luminescence in a longitudinal magnetic field have been measured in nitrogen alloys GaAsN under circularly polarized pumping. It has been found that these dependences are shifted with respect to zero field by a value Beff. The magnitude of the internal field Beff increases with increase in pumping intensity and reaches saturation (~250 Gauss) at great densities of excitation. The saturation of the Beff field with growth of pumping indicates that this is a field of nuclei, polarized dynamically due to hyperfine interaction with optically oriented deep paramagnetic centers, rather than a field of exchange interaction created on the center by spin-polarized photo-excited conduction electrons. The short time of nuclear polarization by electrons (<15 mks), measured under modulation of circular polarization of the exciting light with high frequency, points to a small number of nuclei undergoing hyperfine interaction with an electron localized at a center.

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V. K. Kalevich, M. M. Afanasiev, A. Yu. Shiryaev, A. Yu. Egorov. 2012-10-11. Optical orientation of nuclei in nitrogen alloys GaAsN at room temperature. https://doi.org/10.1134/s0021364012210060

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