We investigate the spin dynamics of high-mobility two-dimensional electrons in GaAs/AlGaAs quantum wells grown along the [001] and [110] directions by time-resolved Faraday rotation at low temperatures. In measurements on the (001)-grown structures without external magnetic fields, we observe coherent oscillations of the electron spin polarization about the effective spin-orbit field. In non-quantizing magnetic fields applied normal to the sample plane, the cyclotron motion of the electrons rotates the effective spin-orbit field. This rotation leads to fast oscillations in the spin polarization about a non-zero value and a strong increase in the spin dephasing time in our experiments. These two effects are absent in the (110)-grown structure due to the different symmetry of its effective spin-orbit field. The measurements are in excellent agreement with our theoretical model.
@article{arxiv.0910.2847,
title = {Cyclotron effect on coherent spin precession of two-dimensional electrons},
author = {M. Griesbeck and M. M. Glazov and T. Korn and E. Ya. Sherman and D. Waller and C. Reichl and D. Schuh and W. Wegscheider and C. Schüller},
journal= {arXiv preprint arXiv:0910.2847},
year = {2011}
}