Defect Conformal Manifolds along RG Domain Walls between $\mathbb Z_N$-Parafermions and Minimal Models

Abstract

We investigate the renormalization group (RG) domain walls interpolating between the $\mathbb{Z}_N$ parafermion theory (the critical $N$-state Potts model) and the Virasoro minimal model $\mathcal{M}_{N+1}$. These flows are genuinely non-perturbative and an explicit construction of Gaiotto type RG domain wall remains elusive. We bypass this limitation by employing a bottom-up approach centered on the emergence of ``phantom currents". By tracking the preserved non-invertible symmetries ($\mathfrak{so}(3)_N$) along the flow, we extract the exact spectrum of these currents localized on the defect. We demonstrate that the presence of a spin-1 phantom current allows the interface to be marginally deformed, dynamically generating a continuous defect conformal manifold. Furthermore, we show that an extra spin-2 operator, crucially as a $W^{(3)}$-algebra descendant of the spin-1 phantom current, rigidly constrains the UV-IR stress tensor mixing via the cluster decomposition principle. This algebraic framework enables the exact computation of the parameter-dependent transmission rate across the conformal manifold, which we observe strictly vanishes in the large-$N$ limit as a consequence of macroscopic target space collapse.