Exploring universal and nonuniversal regimes of trimers from three-body interactions in one-dimensional lattices

Abstract

We investigate the formation of trimers in an infinite one-dimensional lattice model with singleparticle hopping t and hard-core two-body U and three-body V interactions of relevance to Rydberg atoms and polar molecules. For sufficiently attractive U ≤ −2t and positive V > 0 a large trimer is stabilized, which persists as V → ∞, while both attractive U ≤ 0 and V ≤ 0 bind a small trimer. Surprisingly, the excited state above this small trimer is also bound and has a large extent; its behavior as V → −∞ resembles that of the large ground-state trimer.