G -factors in LaAlO₃/SrTiO₃ quantum dots

We investigate the g-factors of individual electron states in gate-defined quantum dots fabricated from LaAlO3/SrTiO3 heterostructures. We consider both the case of effective positive charging energy (U>0) where single electrons are added upon increasing the local gate voltage, and the case of U<0 where electron pairing is observed.

The g-factors are extracted from the field dependence of the quantum dot addition spectrum. Tunnel couplings and confinement are tunable by the gate voltages and in the regime of weakest coupling, we find g-factors close to 2 due to quenching of the orbital magnetic moment. For stronger coupling, g-factors are anisotropic and exhibit values up to ∼4.5 in the out-of-plane orientation.

We further show examples of the sequential addition of electrons with the same spin as a consequence of exchange interactions.