Borromean states in discrete-time quantum walks

Marcin Markiewicz, Marcin Karczewski, Pawel Kurzynski

Published 2020-05-27Version 1

We consider discrete-time quantum walks of many interacting particles. For a specific kind of pairwise interaction, we find peculiar multipartite bound states which fall apart if any subsystem is removed. This provides a conceptually simple physical model of structures known as Borromean rings. Interestingly, our approach highlights the role of entanglement in such systems. In order to form a Borromean bound state, the particles need to exhibit Greenberger-Horne-Zeillinger (GHZ) entanglement. Moreover, we discuss our findings in the context of formation of composite particles.