Dynamics of Hole Singlet-Triplet Qubits with Large g-Factor Differences

The spin-orbit interaction permits to control the state of a spin qubit via electric fields. For holes it is particularly strong, allowing for fast all electrical qubit manipulation, and yet an in-depth understanding of this interaction in hole systems is missing. Here we investigate, experimentally and theoretically, the effect of the cubic Rashba spin-orbit interaction on the mixing of the spin states by studying singlet-triplet oscillations in a planar Ge hole double quantum dot. Landau-Zener sweeps at different magnetic field directions allow us to disentangle the effects of the spin-orbit induced spin-flip term from those caused by strongly site-dependent and anisotropic quantum dot g tensors. Our work, therefore, provides new insights into the hole spin-orbit interaction, necessary for optimizing future qubit experiments.

Automated summary

In this study, we investigate the effect of the cubic Rashba spin-orbit interaction on the mixing of spin states in a planar Ge hole double quantum dot. Our results show that the spin-flip term induced by the spin-orbit interaction has a significant impact on the spin state mixing. This finding is important for optimizing future qubit experiments.