Mesoscopic dipolar quantum crystals

TL;DR

This paper investigates the ground states of mesoscopic two-dimensional dipolar quantum crystals, revealing quantum-stabilized non-classical structures and phase transitions from superfluid to crystalline states through computer simulations.

Contribution

It introduces the first detailed simulation study of mesoscopic dipolar quantum crystals, highlighting quantum effects in non-classical structures and phase behavior.

Findings

Clusters transition from superfluid to supersolid to crystal with increased confinement.

Non-classical crystalline structures are stabilized by quantum effects at specific particle numbers.

Coexistence of quantum and classical configurations occurs at finite temperature.

Abstract

The ground state of a two-dimensional, harmonically confined mesoscopic assembly of up to thirty polar molecules is studied by computer simulations. As the strength of the confining trap is increased, clusters evolve from superfluid, to supersolid, to insulating crystals. For strong confinement, the crystalline structure can be predicted based on classical energetics. However, clusters of specific numbers of particles (i.e., N=12 and N=19) display a {\it non-classical crystalline structure}, stabilized by quantum effects, in an intermediate range of confinement strength. In these cases, coexistence of quantum and classical crystalline configurations is observed at finite temperature.