A new realization of the long-range entanglement: fractality replacing the topological order

Abstract: The essence of the famed long-range entanglement as revealed in topologically ordered state is the paradoxical coexistence of short-range correlation and nonlocal information that cannot be removed through constant-depth local quantum circuits. Its realization in different quantum states is a focus research topic in both quantum computation and quantum matter. However, the proved realizations are subject to the paradigm of topological order (including its extensions), i.e. via a quantum code structure with macroscopic code distance. Here, we broaden the knowledge of long-range entangled states by rigorously proving the coexistence in a new concrete state. The state describes qudits on the newly experimentally discovered fractal lattice geometry (1.58D) on which the quantum code structure has been shown not to exist, i.e., there is no topological order. Our result might reveal a new paradigm for the realization of the long-range entanglement in many-body quantum states, and might stimulate new studies connecting quantum information and quantum matter.