Observing structural disorder induced interacting topological phase in an atom array

Abstract: Topological phases of matter can appear in noninteracting systems, as in band topology, or interacting systems, such as in spin models, with their defining features typically robust against weak disorder. Intriguingly, disorder itself can also induce topological phases--exemplified by the Anderson topological insulator in noninteracting systems. Experimental studies on disorder induced topology have so far been limited to band topology. Here we report direct observations of structural disorder induced many-body interacting topological phase in an atom array at half-filling, whereby random offsets to tweezer locations forming a lattice implement structural disorder, causing fluctuating long-range dipolar interactions between tweezer confined single atoms. The ground state degeneracy in disordered configurations is detected and compared to a regular lattice. The induced topological phase is also vindicated by the spatially resolved atom-atom correlation functions for different forms of dimer compositions. By probing the quench dynamics of a highly excited state, we observe markedly slower decay of edge spin magnetization in comparison to the bulk spin one, consistent with the presence of topologically protected edge modes in disordered lattices. Our experiments open a new direction for studying the interplay between structural disorder and strongly interacting topological matter in Rydberg atom arrays.