Ground state of low dimensional dipolar gases: linear and zigzag chains

TL;DR

This paper investigates the phase transitions and structural patterns of ultracold dipolar gases in anisotropic traps, revealing how classical and quantum effects influence the emergence and disappearance of transverse configurations like zigzag chains.

Contribution

It provides a combined classical and quantum Monte Carlo analysis of the phase diagram, identifying critical transverse frequencies for pattern formation and showing quantum fluctuations suppress these patterns.

Findings

Classical theory predicts critical transverse frequencies for pattern transitions.

Quantum fluctuations smooth and eliminate the classical phase transitions.

Results are experimentally testable and highlight zero-point motion effects.

Abstract

We study the ground state phase diagram of ultracold dipolar gases in highly anisotropic traps. Starting from a one-dimensional geometry, by ramping down the transverse confinement along one direction, the gas reaches various planar distributions of dipoles. At large linear densities, when the dipolar gas exhibits a crystal-like phase, critical values of the transverse frequency exist below which the configuration exhibits novel transverse patterns. These critical values are found by means of a classical theory, and are in full agreement with classical Monte Carlo simulations. The study of the quantum system is performed numerically with Monte Carlo techniques and shows that the quantum fluctuations smoothen the transition and make it completely disappear in a gas phase. These predictions could be experimentally tested and would allow one to reveal the effect of zero-point motion on self-organized mesoscopic structures of matter waves, such as the transverse pattern of the zigzag chain.