Relaxation and dephasing of hole spins are measured in a gate-defined Ge/Si nanowire double quantum dot using a fast pulsed-gate method and dispersive readout. An inhomogeneous dephasing time T2∗∼0.18μs exceeds corresponding measurements in III-V semiconductors by more than an order of magnitude, as expected for predominately nuclear-spin-free materials. Dephasing is observed to be exponential in time, indicating the presence of a broadband noise source, rather than Gaussian, previously seen in systems with nuclear-spin-dominated dephasing.
@article{arxiv.1403.2093,
title = {Hole Spin Coherence in a Ge/Si Heterostructure Nanowire},
author = {A. P. Higginbotham and T. W. Larsen and J. Yao and H. Yan and C. M. Lieber and C. M. Marcus and F. Kuemmeth},
journal= {arXiv preprint arXiv:1403.2093},
year = {2014}
}