  We prove that a special alternating knot does not decompose as a non-trivial
band sum. This restricts concordances from special alternating knots, and we
conjecture that special alternating knots are ribbon concordance minimal. We
verify our conjecture in many cases. This work is motivated by another
conjecture of Owens and the second author, which posits that the set of
alternating knots is downward closed under ribbon concordance.
