Electrical control of the g tensor of the first hole in a silicon MOS quantum dot

Hole spins are highly promising for spin-qubit technology due to the ability to electrically manipulate the hole g tensor. However, gaps remain in our understanding of the mechanisms that couple hole spins to electric fields. Here, the authors investigate the effect of unintentional strain on the spin state of a single hole confined in a metal-oxide-semiconductor (MOS) quantum dot. Results show that the metal electrodes produce a nonuniform strain profile, resulting in nanometer-scale variations in the heavy-hole--light-hole splitting. Therefore, local electric fields can be used to displace the hole wavefunction relative to the nonuniform strain, allowing a mechanism for electric control of the hole g tensor.