Dipoles on a Two-leg Ladder

TL;DR

This study investigates how polar molecules with long-range dipole interactions behave on a two-leg ladder, revealing angle-dependent ordering phenomena and potential experimental observability.

Contribution

It introduces a detailed analysis of dipolar interactions on a ladder geometry, highlighting the critical angle for ordering disappearance based on dipole orientation.

Findings

Zig-zag ordering occurs with predominantly repulsive interactions.

A critical angle exists where ordering vanishes.

Behavior is observable with current experimental setups.

Abstract

We study polar molecules with long-range dipole-dipole interactions confined to move on a two-leg ladder for different orientations of the molecular dipole moments with respect to the ladder. Matrix product states are employed to calculate the many-body ground state of the system as function of lattice filling fractions, perpendicular hopping between the legs, and dipole interaction strength. We show that the system exhibits zig-zag ordering when the dipolar interactions are predominantly repulsive. As a function of dipole moment orientation with respect to the ladder, we find that there is a critical angle at which ordering disappears. This angle is slightly larger than the angle at which the dipoles are non-interacting along a single leg. This behavior should be observable using current experimental techniques.