Electric control of the single hole g-factor by 400% in a silicon MOS quantum dot.

Holes in silicon quantum dots are attracting significant attention for their potential use as fast, highly coherent spin qubits [1]. However, there are still gaps in the understanding of the physics of hole spins. For example, the full effects of confinement and spin-orbit coupling on hole spin states remains an open problem. Studies of the Lande g-tensor are valuable for characterizing this underlying spin physics, however most studies of holes have been performed in an unknown orbital configuration where spin-orbit coupling can lead to complex non-trivial spin effects. Studies of a single hole in a known and reproducible orbital state can therefore provide valuable insight into the complex spin physics.

In this work we confine a single hole in a known orbital state [2] and study the Lande g-tensor using a 3D vector magnet. We compare the g-tensor for different confinement profiles and find the g-tensor can be strongly modulated and even rotated by up to 30 degrees. These results show that the anisotropy of the single hole g-tensor is due to symmetries in the tunable electric confinement. This tunability can be harnessed for further use of holes in spin qubit applications.

[1] C. Kloeffel et al., Phys. Rev. B 88, 241405 (2013)
[2] S. D. Liles et al., Nature Communications 9 (2018)