Exact Quantum Many-Body Scars in 2D Quantum Gauge Models
arXiv:2505.21921 · doi:10.22331/q-2026-07-18-2164
The paper identifies exact quantum many-body scar states in a two‑dimensional Z₂ gauge model by exploiting its duality to a spin‑½ XY model on bipartite graphs, showing that these scar states form a tower of exact eigenstates.
Abstract
Quantum many-body scars (QMBS) serve as important examples of ergodicity-breaking phenomena in quantum many-body systems. Despite recent extensive studies, exact QMBS are rare in dimensions higher than one. In this paper, we study a two-dimensional quantum gauge model that is dual to a two-dimensional spin- XY model defined on bipartite graphs. We identify the exact eigenstates of the XY model with a tower structure as exact QMBS. Exploiting the duality transformation, we show that the exact QMBS of the XY model (and XXZ model) after the transformation are the exact QMBS of the dual gauge model. This construction is versatile and has potential applications for finding new QMBS in other higher-dimensional models.
44 pages, 21 figures