Single and two hole spin qubits formed in a lateral GaAs/AlGaAs double quantum dot

Single holes localised in electrostatically tuneable quantum dot devices are explored as candidates for spin qubits. Here we study single hole and two-hole hybrid spin-charge qubits in the presence of a strong spin-orbit interaction. For the single hole regime we present results on the
Landau-Zener-Stuckelberg (LZS) interferometry involving spin conserving and spin-flip processes. LZS patterns evolve with microwave frequency from discreet (often referred as PAT) at high frequencies to continuous LZS fringes at low frequencies. Taking LZS measurements at different magnetic fields we observe two separate sets of LZS fringes offset by the Zeeman energy. The magnetic field dependence of the single hole spin relaxation time is measured, taking advantage of the latching technique we originally developed for electron spin qubits [1-2] and which is rapidly being adopted as a standard technique for high fidelity measurements. Additionally, we extend LZS measurements to the two-hole case near the (02)-(11) transition and present results from LZS interferometry of the singlet/triplet spin qubit states.
[1] S. A. Studenikin, et al., Appl. Phys. Lett. {\bf 101}, 233101 (2012).
[2] J. D. Mason, et al., Phys. Rev. B {\bf 92}, 125434 (2015)