  Through magneto-transport measurements and analysis of the observed Shubnikov
de Haas oscillations in (010) (AlxGa1-x)2O3/Ga2O3 heterostructures,
spin-splitting of the Landau levels in the (010) Ga2O3 two-dimensional electron
gas (2DEG) has been studied. Analysis indicates that the spin-splitting results
from the Zeeman effect. By fitting the both the first and second harmonic of
the oscillations as a function of magnetic field, we determine the magnitude of
the Zeeman splitting to be 0.4$\hbar\omega_c$, with a corresponding effective
g-factor of 2.7, for magnetic field perpendicular to the 2DEG.
