Bound states of Dipolar Bosons in One-dimensional Systems

TL;DR

This paper investigates the formation of bound states of dipolar bosons in one-dimensional tubes, analyzing few-body structures and effective many-body models based on dipole interactions and polarization angles.

Contribution

It introduces a comprehensive analysis of few-body bound states in dipolar bosonic systems with variable polarization, and develops an effective model for many-body physics.

Findings

Inter-tube interactions resemble zero-range potentials with rescaled strength.

Bound chains with one molecule per tube serve as effective degrees of freedom.

Exact solutions are applicable to the mapped many-body Hamiltonians.

Abstract

We consider one-dimensional tubes containing bosonic polar molecules. The long-range dipole-dipole interactions act both within a single tube and between different tubes. We consider arbitrary values of the externally aligned dipole moments with respect to the symmetry axis of the tubes. The few-body structures in this geometry are determined as function of polarization angles and dipole strength by using both essentially exact stochastic variational methods and the harmonic approximation. The main focus is on the three, four, and five-body problems in two or more tubes. Our results indicate that in the weakly-coupled limit the inter-tube interaction is similar to a zero-range term with a suitable rescaled strength. This allows us to address the corresponding many-body physics of the system by constructing a model where bound chains with one molecule in each tube are the effective degrees of freedom. This model can be mapped onto one-dimensional Hamiltonians for which exact solutions are known.