Quantum Hall Ferromagnets are a unique platform to study the confluence of symmetry-broken order parameter and topological physics. Recent experiments by Feldman et al. observe clear signatures of valley-polarized Quantum Hall Ferromagnets on the surface of Bi(111) in the presence of strong magnetic fields. The tunneling conductance shows a discrete spectrum indicating the formation of Landau levels while individual nematic Landau level orbits pinned to impurities indicate selective occupation of certain valleys. Further recent experiments observe domain wall states between such nematic domains. Curiously, these domain walls appear to host low energy excitations that appear to be gapped/gapless depending on the filling fraction of the nematic quantum Hall states. We explain these observations both qualitatively and quantitatively by highlighting the role of interactions and symmetries in engendering such exotic Luttinger liquids.
 B. Feldman et al., Science 2016
 M. T. Randeria, KA et al., Nature 2019
 KA et al., ArXiv:1807.10293