Quantum Many Body Scars from Emergent Chiral Symmetry in a Density-Difference-Dependent Gauge Field

Quantum Many Body Scars (QMBS) are a set of energy eigenstates that violate ergodicity in a quantum setting, promoting the non-thermalization of a system for certain initial conditions. QMBS represent a unique violation of the ergodic principle in statistical mechanics, which only occurs for a relatively small portion of the Hilbert space. Here we report on the existence of QMBS in the presence of a density-difference-dependent gauge field in 1D. We have found two distinct mechanisms for QMBS formation. The first mechanism forms charge density wave-like scars by destructive interference between single particle hopping and correlated hopping. The second mechanism results in scars of many body edge modes pinned to zero energy by an emergent chiral symmetry, which can be thought of as an analogue to the topological SSH edge mode. These results demonstrate how symmetries, particularly emergent symmetries, can be useful in stabilizing QMBS and provide two mechanisms for realizing such non-ergodic states.