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arXiv · 1201.1123

Measurements of a fast nuclear spin dynamics in a single InAs quantum dot with positively charged exciton

X. M. Dou·B. Q. Sun·D. S. Jiang·H. Q. Ni·Z. C. Niu
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Abstract

By using highly time-resolved spectroscopy with an alternative σ+/σ - laser pulse modulation technique, we are able to measure the fast buildup and decay times of the dynamical nuclear spin polarization (DNSP) at 5 K for a single InAs quantum dot (QD) with positively charged exciton. It is shown that the nuclear dipole-dipole interaction can efficiently depolarize DNSP with a typical time constant of 500 μs in the absence of external magnetic field. By using an external field of 8 mT to suppress the nuclear dipolar interaction, the decay time turns to be mainly induced by interaction with unpaired electron and extends to about 5 ms. In addition, it is found that the time constant of hole-induced depolarization of nuclear spin is about 112 ms.

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X. M. Dou, B. Q. Sun, D. S. Jiang, H. Q. Ni, Z. C. Niu. 2012-01-05. Measurements of a fast nuclear spin dynamics in a single InAs quantum dot with positively charged exciton. https://doi.org/10.1209/0295-5075%2F98%2F17007

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