Observation of spin splitting in single InAs self-assembled quantum dots in AlAs

Using magneto-tunneling spectroscopy, we observe the Zeeman spin splitting of the ground state of a single InAs quantum dot grown within AlAs. We obtain values for the g factor of different quantum dots between $\text{+0.52±0.08}$ and $\text{+1.6±0.2,}$ with magnetic field applied in the plane of the dot. This value for the g factor is considerably different from that of bulk InAs $\text{(g=−14.8),}$ and we explain this using a simple three band ${k\cdot p}$ calculation. Using the spin split states of the dot as a probe, we observe the complete spin polarization of the emitter accumulation layer.