Symmetry protected quantum many body scars through half-gauging

Abstract: We study the interplay between symmetry defects insertion and the phenomena of quantum many body scarring. We exploit a class of models obtained from an embedding mechanism that defines a stochastic matrix form hamiltonian, hosting zero energy many body scarred states. Such models display an interesting playground to explore the consequences of dualities, half-gauging operations and so on. We first show that inside this class of models, what are the conditions to still have scared states after defect insertion. The main result of our work is a detailed analysis of half-gauging in such chains, which introduces a non-trivial interface in our system, leading to scarred states protected by the underlying symmetries. The conclusions for half-gauged scarred systems are general and may lead to fruitful directions for higher dimension scarred physics and their robustness.