Scaling and Lüscher term in a non-Abelian (2+1)d SU(2) quantum link model

We investigate a non-Abelian SU(2) quantum link model in $$2+1$$ 2 + 1 dimensions on a hexagonal lattice using tensor network methods. We determine the static quark potential for a wide range of bare coupling values and find that the theory is confining. We also probe the existence of a Lüscher term and find a clear signal with a g² g 2 dependent coefficient, in qualitative agreement with a strong coupling expansion. Correspondingly, the width of the strings scales logarithmically with the string length again for all g² g 2 -values, providing evidence for a rough string, with no indication for a roughening transition.