  The magnetic-field evolution of Coulomb blockade peaks in lateral
InGaAs/InAlAs quantum dots in the few-electron regime is reported. Quantum dots
are defined by gates evaporated onto a 60 nm-thick hydrogen silsesquioxane
insulating film. A gyromagnetic factor of 4.4 is measured via zero-bias spin
spectroscopy and a transition from singlet to triplet spin configuration is
found at an in-plane magnetic field B = 0.7 T. This observation opens the way
to the manipulation of singlet and triplet states at moderate fields and its
relevance for quantum information applications will be discussed.
