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arXiv · 0710.2837

Overhauser effect in individual InP/GaInP dots

J. Skiba-Szymanska·A. V. Nikolaenko·E. A. Chekhovich·A. I. Tartakovskii·M. N. Makhonin·I. Drouzas·M. S. Skolnick·A. B. Krysa
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Abstract

Sizable nuclear spin polarization is pumped in individual InP/GaInP dots in a wide range of external magnetic fields B_ext=0-5T by circularly polarized optical excitation. We observe nuclear polarization of up to ~40% at Bext=1.5T and corresponding to an Overhauser field of ~1.2T. We find a strong feedback of the nuclear spin on the spin pumping efficiency. This feedback, produced by the Overhauser field, leads to nuclear spin bi-stability at low magnetic fields of Bext=0.5-1.5T. We find that the exciton Zeeman energy increases markedly, when the Overhauser field cancels the external field. This counter-intuitive result is shown to arise from the opposite contribution of the electron and hole Zeeman splittings to the total exciton Zeeman energy.

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J. Skiba-Szymanska, A. V. Nikolaenko, E. A. Chekhovich, A. I. Tartakovskii, M. N. Makhonin, I. Drouzas, M. S. Skolnick, A. B. Krysa. 2008-03-14. Overhauser effect in individual InP/GaInP dots. https://doi.org/10.1103/physrevb.77.165338

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