  We find that the topological phase transition in a chiral ladder is
characterized by dramatic signatures in many body entanglement entropy between
the legs, close to half-filling. The value of entanglement entropy for various
fillings close to half-filling is identical, at the critical point, but splays
out on either side, thus showing a sharp signature at the transition point. A
second signature is provided by the change in entanglement entropy when a
particle is added (or subtracted) from half-filling which turns out to be
exactly $-\log{2}$ in the trivial phase, but zero in the topological phase. A
microscopic understanding of tendencies to form singlets along the rungs in the
trivial phase, and along the diagonals in the topological phase, is afforded by
a study of concurrence. At the topological phase transition the magnitude of
the derivative of the average concurrence of all the rungs shows a sharp peak.
Also, at the critical point, the average concurrence is the same for various
fillings close to half-filling, but splays out on either side, just like
entanglement entropy.
