  This work reports an investigation of electron transport in monoclinic
\beta-Ga2O3 based on a combination of density functional perturbation theory
based lattice dynamical computations, coupling calculation of lattice modes
with collective plasmon oscillations and Boltzmann theory based transport
calculations. The strong entanglement of the plasmon with the different
longitudinal optical (LO) modes make the role LO-plasmon coupling crucial for
transport. The electron density dependence of the electron mobility in
\beta-Ga2O3 is studied in bulk material form and also in the form of
two-dimensional electron gas. Under high electron density a bulk mobility of
182 cm2/ V.s is predicted while in 2DEG form the corresponding mobility is
about 418 cm2/V.s when remote impurities are present at the interface and
improves further as the remote impurity center moves away from the interface.
The trend of the electron mobility shows promise for realizing high electron
mobility in dopant isolated electron channels. The experimentally observed
small anisotropy in mobility is traced through a transient Monte Carlo
simulation. It is found that the anisotropy of the IR active phonon modes is
responsible for giving rise to the anisotropy in low-field electron mobility.
