The coherent electron spin dynamics of an ensemble of singly charged (In,Ga)As/GaAs quantum dots in a transverse magnetic field is driven by periodic optical excitation at 1 GHz repetition frequency. Despite the strong inhomogeneity of the electron g factor, the spectral spread of optical transitions, and the broad distribution of nuclear spin fluctuations, we are able to push the whole ensemble of excited spins into a single Larmor precession mode that is commensurate with the laser repetition frequency. Furthermore, we demonstrate that an optical detuning of the pump pulses from the probed optical transitions induces a directed dynamic nuclear polarization and leads to a discretization of the total magnetic field acting on the electron ensemble. Finally, we show that the highly periodic optical excitation can be used as universal tool for strongly reducing the nuclear spin fluctuations and preparation of a robust nuclear environment for subsequent manipulation of the electron spins, also at varying operation frequencies.

横向磁场中单电荷（In，Ga）As / GaAs量子点集合的相干电子自旋动力学由1 GHz重复频率的周期性光激发驱动。尽管电子g的非均质性很强因子，光学跃迁的光谱扩展以及核自旋波动的广泛分布，我们能够将整个激发的自旋整体推向与激光重复频率相当的单个拉莫尔进动模式。此外，我们证明了从探测到的光学跃迁中抽运脉冲的光学失谐会引起定向的动态核极化，并导致作用在电子集合上的总磁场离散化。最后，我们证明了高度周期性的光激发可以用作通用工具，以强烈减少核自旋波动并为随后的电子自旋操纵（也包括在不同的工作频率下）准备一个健壮的核环境。