Optical orientation of nuclei in nitrogen alloys GaAsN at room temperature

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.

6 pages, 2 figures, Accepted by JETP Letters

References in corpus (1)

• Spin relaxation of localized electrons in n-type semiconductors

Cited by in corpus (9)

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• Electron-nucleus spin correlation conservation of the spin dependent recombination in Ga${}^{2+}$ centers
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