  Both the Haldane spin chain and a topologically dimerized chain feature
topologically protected edge states that are expected to be robust against some
kind of noise. To elucidate whether it might be feasible to create such edge
states in dimerized chains in a controlled manner in solid states environments,
e.g. as spin chains on surfaces, as has already been successfully achieved with
the Haldane chain, we investigate their robustness with respect to long-range
coupling, anisotropies and finite chain length. The theoretical investigation
is based on an alternating Heisenberg spin chain with spin-1/2, which is
investigated using exact diagonalization. We find that dimerized chains and
Haldane chains have robustness against long-range coupling and anisotropies. In
particular, dimerized spin chains are significantly more robust than Haldane
chains
