Dimensional Crossover in the Superfluid-Supersolid Quantum Phase Transition

Year: 2021

Authors: Biagioni G., Antolini N., Alana A., Modugno M., Fioretti A., Gabbanini C., Tanzi ., Modugno G.

Autors Affiliation: CNR INO, Sede Pisa, I-56124 Pisa, Italy; Univ Florence, Dept Phys & Astron, I-50019 Sesto Fiorentino, Italy; Univ Florence, LENS, I-50019 Sesto Fiorentino, Italy; Univ Basque Country UPV EHU, Dept Phys, Bilbao 48080, Spain; Basque Fdn Sci, IKERBASQUE, Bilbao 48013, Spain

Abstract: Supersolids are a fundamental quantum phase of matter where the global phase and translational symmetries are spontaneously broken. The recently discovered supersolidity in quantum gases of strongly magnetic atoms gives the opportunity to explore in depth how superfluidity and crystalline order are mixed in this fascinating phase. The dipolar supersolid is usually created from a Bose-Einstein condensate, i.e., a standard superfluid, crossing a quantum phase transition that is related to the crystallization transitions of ordinary matter. In this work, we assess experimentally and theoretically the character of the superfluid-supersolid quantum phase transition. 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 dimensional crossover is peculiar to supersolids, is controlled via the transverse confinement and the atom number, and can be justified on the general ground of the Landau theory of phase transitions. The quasiadiabatic crossing of a continuous phase transition opens new directions of investigation for supersolids.

Journal/Review: PHYSICAL REVIEW X

Volume: 12 (2)      Pages from: 021019-1  to: 021019-18

More Information: We acknowledge discussions with I. L. Egusquiza and A. Smerzi. This work was supported by the EC-H2020 research and innovation program, through the Project No. 641122-QUIC, by the QuantERA grant MAQS, by Consiglio Nazionale delle Ricerche-Istituto Nazionale di Ottica (CNR-INO), by Grant No. PGC2018-101355-B-I00 funded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe, and by the Basque Government through Grant No. IT986-16.
KeyWords: supersolids; transition
DOI: 10.1103/PhysRevX.12.021019