Impact of hole- g -factor anisotropy on spin-photon entanglement generation with (In, Ga) As quantum dots

Self-assembled InGaAs/GaAs quantum dots (QDs) are of particular importance for the deterministic generation of spin-photon entanglement. One promising scheme relies on the Larmor precession of a spin in a transverse magnetic field, which is governed by the in-plane g factors of the electron and the valence-band heavy hole. We probe the origin of heavy-hole g-factor anisotropy with respect to the in-plane magnetic field direction and uncover how it impacts the entanglement generated between the spin and the photon polarization. First, using polarization-resolved photoluminescence measurements on a single QD, we determine that the impact of valence-band mixing dominates over effects due to a confinement-renormalized cubic Luttinger q parameter. From this, we construct a comprehensive hole g-tensor model. We then use this model to simulate the concurrence and fidelity of spin-photon entanglement generation with anisotropic hole g factors, which can be leveraged by tuning the magnetic field angle and the excitation polarization. The results demonstrate that postgrowth control of the hole g factor can be used to improve spin-photon cluster-state generation.