  With the recent observation of graphene-like Landau levels at the surface of
topological insulators, the possibility of fractional quantum Hall effect,
which is a fundamental signature of strong correlations, has become of
interest. Some experiments have reported intra-Landau level structure that is
suggestive of fractional quantum Hall effect. This paper discusses the
feasibility of fractional quantum Hall effect from a theoretical perspective,
and argues that while this effect should occur, ideally, in the $n=0$ and
$|n|=1$ Landau levels, it is ruled out in higher $|n|$ Landau levels. Unlike
graphene, the fractional quantum Hall effect in topological insulators is
predicted to show an interesting asymmetry between $n=1$ and $n=-1$ Landau
levels due to spin-orbit coupling.
