Quenched activity induces nonuniversal scaling in nonreciprocal XY Models and surfaces

Abstract: Active XY models and active surfaces are two paradigmatic nonequilibrium systems with distinct microscopic origins. We show that the hydrodynamic theories for a quenched-disordered nonreciprocal random bond two-dimensional XY model and an inversion-symmetric active surface tangentially advected by quenched velocities are identical. This theory predicts sub-logarithmic phase order in the XY model and sub- or super-logarithmic positional order in the surface for short-range disorder with nonuniversal exponents, which vary continuously with the degree of transversality of the disorder variance. We argue that the nonreciprocal random bond XY model can disorder through vortex proliferation.