Dimensional crossover in the superfluid-supersolid quantum phase transition

TL;DR

This paper investigates the nature of the superfluid-supersolid quantum phase transition in dipolar quantum gases, revealing a controllable crossover between discontinuous and continuous transitions influenced by confinement and atom number.

Contribution

It provides experimental and theoretical evidence of a dimensional crossover in the phase transition, linking it to Landau theory and highlighting new research directions.

Findings

Identification of two types of phase transitions in supersolids

Control of transition type via confinement and atom number

Observation of a smooth crossover between transition regimes

Abstract

We assess experimentally and theoretically the character of the superfluid-supersolid quantum phase transition recently discovered in trapped dipolar quantum gases. We find that one-row supersolids can have already two types of phase transitions, discontinuous and continuous, that are reminiscent of the first- and second-order transitions predicted in the thermodynamic limit in 2D and 1D, respectively. The smooth crossover between the two regimes is peculiar to supersolids and can be controlled via the transverse confinement and the atom number. We justify our observations on the general ground of the Landau theory of phase transitions. The quasi-adiabatic crossing of a continuous phase transition opens new directions of investigation for supersolids.