Long-range entanglement and topological excitations

Abstract

Topological order comes in different forms, and its classification and detection is an important field of modern research. In this work, we show that the Disconnected Entanglement Entropy, a measure originally introduced to identify topological phases, is also able to unveil the long-range entanglement (LRE) carried by a single, fractionalized excitation. We show this by considering a quantum, delocalized domain wall excitation that can be introduced into a system by inducing topological frustration in an antiferromagnetic spin chain. Furthermore, we study the resilience of LRE against a quantum quench and the introduction of disorder, thus establishing the existence of a phase with topological features despite not being a typical topological order or symmetry-protected one.