  Among the many facets of quantum correlations, bound entanglement has
remained one the most enigmatic phenomena, despite the fact that it was
discovered in the early days of quantum information. Even its detection has
proven to be difficult, let alone its precise quantitative characterization. In
this work, we present the exact quantification of entanglement for a
two-parameter family of highly symmetric two-qutrit mixed states, which
contains a sizable part of bound entangled states. We achieve this by
explicitly calculating the convex-roof extensions of the linear entropy as well
as the concurrence for every state within the family. Our results provide a
benchmark for future quantitative studies of bipartite entanglement in
higher-dimensional systems.
