We use extensive density-matrix renormalization-group calculations to show that a classification of $\text{SU}\left(n\right)$ spin chains with regard to the existence of spinon confinement and hence a Haldane gap obtained previously for valence bond solid models applies to $\text{SU}\left(n\right)$ Heisenberg chains as well. In particular, we observe spinon confinement due to a next-nearest-neighbor interaction in the SU(4) representation 10 chain.

• Received 2 September 2009

DOI:https://doi.org/10.1103/PhysRevB.80.180420