Universal bound states of one-dimensional bosons with two- and three-body attractions

Yusuke Nishida

When quantum particles are confined into lower dimensions, an effective three-body interaction inevitably arises and may cause significant consequences. Here we study bosons in one dimension with weak two-body and three-body interactions, predict the existence of two three-body bound states when both interactions are attractive, and determine their binding energies as universal functions of the two-body and three-body scattering lengths. We also show that an infinitesimal three-body attraction induces an excited bound state only for 3, 39, or more bosons. Our findings herein have direct relevance to a broad range of quasi-one-dimensional systems realized with ultracold atoms.

裕太 関野, Yuta Sekino, Yusuke Nishida

Yusuke Nishida

When quantum particles are confined into lower dimensions, an effective three-body interaction inevitably arises and may cause significant consequences. Here we study bosons in one dimension with weak two-body and three-body interactions and predict the existence of two three-body bound states when both interactions are attractive. Their binding energies are universal functions of the two-body and three-body scattering lengths and have direct relevance to a broad range of quasi-one-dimensional systems realized with ultracold atoms.

L. Platter, H.-W. Hammer, Ulf-G. Meißner

Walter Greiner, Berndt Müller, Johann Rafelski A

Yuta Sekino, Yusuke Nishida

Ultracold atoms offer valuable opportunities where interparticle interactions can be controlled at will. In particular, by extinguishing the two-body interaction, one can realize unique systems governed by the three-body interaction, which is otherwise hidden behind the two-body interaction. Here we study one-dimensional bosons with a weak three-body attraction and show that they form few-body bound states as well as a many-body droplet stabilized by the quantum mechanical effect. Their binding energies relative to that of three bosons are all universal and the ground-state energy of the dilute droplet is found to grow exponentially as ${E}_{N}/{E}_{3}\ensuremath{\rightarrow}exp(8{N}^{2}/\sqrt{3}\ensuremath{\pi})$ with increasing particle number $N\ensuremath{\gg}1$. The realization of our system with coupled two-component bosons in an optical lattice is also discussed.