Electronic g factor and tunable spin-orbit coupling in a gate-defined InSbAs quantum dot

We investigate transport properties of stable gate-defined quantum dots formed in an InSb0.87As0.13 quantum well. High g factor and strong spin-orbit coupling make InSbxAs1-x a promising platform for exploration of topological superconductivity and spin-based devices. We extract a nearly isotropic in-plane effective g factor by studying the evolution of Coulomb blockade peaks and differential conductance as a function of the magnitude and direction of magnetic field. The in-plane g factors, |g* [11 over bar 0]| and |g*[110]|, range from 49 to 58. Interestingly, this g factor is higher than that found in quantum dots fabricated from pure InSb quantum wells. We demonstrate tunable spin-orbit coupling by tracking a spin-orbit coupling mediated avoided level crossing between the ground state and an excited state in magnetic field. By increasing the electron density, we observed an increase in an avoided crossing separation, ASO. The maximum energy separation extracted is ASO similar to 100 mu eV.