Scaling and Luescher 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 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 Luescher term and find a clear signal, however, the value of the dimensionless constant $γ$ strongly deviates from the expected universal value $-π/24$ for almost all values of the coupling $g^2$ we investigated. The width of the strings scales logarithmically with the string length again for all $g^2$-values, providing evidence for a rough string, with no indication for a roughening transition.

Source: arXiv:2602.23213v1 - http://arxiv.org/abs/2602.23213v1 PDF: https://arxiv.org/pdf/2602.23213v1 Original Link: http://arxiv.org/abs/2602.23213v1