We present a comprehensive study of electron spin decoherence in bulk germanium. As a first cornerstone, the effective $g$ tensor of $L$-valley electrons in germanium is deduced from time-domain magneto-optical experiments. The decay of the ensemble spin polarization is then found to be closely related to intervalley scattering. In particular, the angular and temperature dependences of the experiment are well described in a model including Elliott-Yafet-type spin-flip processes as well as dephasing due to scattering between valleys exhibiting different effective $g$ factors.

• Received 7 February 2012

DOI:https://doi.org/10.1103/PhysRevB.85.121203