Two-level quantum systems with strong spin-orbit coupling allow for all-electrical qubit control and long-distance qubit coupling via microwave and phonon cavities, making them of particular interest for scalable quantum information technologies. In silicon, a strong spin-orbit coupling exists within the spin-3/2 system of acceptor atoms and their energy levels and properties are expected to be highly tunable. Here we show the influence of local symmetry tuning on the acceptor spin-dynamics, measured in the single-atom regime. Spin-selective tunneling between two coupled boron atoms in a commercial CMOS transistor is utilised for spin-readout, which allows for the probing of the two-hole spin relaxation mechanisms. A relaxation-hotspot is measured and explained by the mixing of acceptor heavy and light hole states. Furthermore, excited state spectroscopy indicates a magnetic field controlled rotation of the quantization axes of the atoms. These observations demonstrate the tunability of the spin-orbit states and dynamics of this spin-3/2 system.
@article{arxiv.1703.03538,
title = {Spin-orbit dynamics of single acceptor atoms in silicon},
author = {J. van der Heijden and T. Kobayashi and M. G. House and J. Salfi and S. Barraud and R. Lavieville and M. Y. Simmons and S. Rogge},
journal= {arXiv preprint arXiv:1703.03538},
year = {2019}
}