  Via large-scale molecular dynamics simulations, we observe the melting of a
topological glass of stiff ring polymers by incorporating flexible ring
polymers, along an isobaric path. As more flexible ring polymers are
introduced, cluster glass-like structures emerge in the stiffer ring polymers
with reduced orthogonal threading. This eventually evolves to a stacked
columnar structure at an increased fraction of flexible ring polymers.
Depletion interactions between the stiff and flexible rings drive the stacking,
contingent on the disparity in flexibility in the ring polymer mixture.
