  The Sachdev-Ye-Kitaev (SYK) model shows chaotic behavior with a maximal
Lyapunov exponent. In this paper, we investigate the four-point function of a
SYK-type model numerically, which gives us access to its Lyapunov exponent. The
model consists of two sets of Majorana fermions, called A and B, and the
interactions are restricted to being exclusively pairwise between the two sets,
not within the sets. We find that the Lyapunov exponent is still maximal at
strong coupling. Furthermore, we show that even though the conformal dimensions
of the A and B fermions change with the population ratio, the Lyapunov exponent
remains constant, not just in the conformal limit where it is maximal, but also
in the intermediate and weak coupling regimes.
