Topological Extended Doublons Formed by Drive-Induced Non-Local Interactions

When studying systems of interacting particles, few-particle systems are of particular interest as the mean-field approximation breaks down for a small number of particles. Two particles with attractive or repulsive long-range interactions may form a bound state [1], the so-called doublon, showing a number of peculiar features: topologically protected doublon states can not only persist outside the parameter regime for topological single particles [2], but also break the bulk boundary correspondence for large interactions [3]. So far doublons were only considered as doubly-occupied lattice sites [1], [4], whereas this work focuses on the general form of quasi-particles extending over multiple lattice sites.