  Intrinsic magnetic topological insulators have emerged as a promising
platform to study the interplay between topological surface states and
ferromagnetism. This unique interplay can give rise to a variety of exotic
quantum phenomena, including the quantum anomalous Hall effect and axion
insulating states. Here, utilizing molecular beam epitaxy (MBE), we present a
comprehensive study of the growth of high-quality MnBi2Te4 thin films on Si
(111), epitaxial graphene, and highly ordered pyrolytic graphite substrates. By
combining a suite of in-situ characterization techniques, we obtain critical
insights into the atomic-level control of MnBi2Te4 epitaxial growth. First, we
extract the free energy landscape for the epitaxial relationship as a function
of the in-plane angular distribution. Then, by employing an optimized
layer-by-layer growth, we determine the chemical potential and Dirac point of
the thin film at different thicknesses. Overall, these results establish a
foundation for understanding the growth dynamics of MnBi2Te4 and pave the way
for the future applications of MBE in emerging topological quantum materials.
