Two-dimensional miscible-immiscible supersolid and droplet crystal state in a homonuclear dipolar bosonic mixture

TL;DR

This paper investigates the rich groundstate phases and dynamics of a binary dipolar bosonic mixture, revealing novel supersolid, droplet, and superfluid states through three-dimensional simulations, with implications for future experiments.

Contribution

It provides the first detailed phase diagram and dynamical analysis of a Dy-Dy dipolar mixture, highlighting new mixed phases and transition mechanisms.

Findings

Identification of various groundstate phases including supersolid, droplet, and superfluid states.

Observation of dynamical transitions between miscible and immiscible droplet states.

Demonstration of formation of supersolid clusters and droplet lattices via scattering length quenches.

Abstract

The recent realization of binary dipolar BEC [Phys. Rev. Lett. 121, 213601 (2018)] opens new exciting aspects for studying quantum droplets and supersolids in a binary mixture. Motivated by this experiment, we study groundstate phases and dynamics of a Dy-Dy mixture. Dipolar bosonic mixture exhibits qualitatively novel and rich physics. Relying on the three-dimensional numerical simulations in the extended Gross-Pitaevskii framework, we unravel the groundstate phase diagrams and characterize different groundstate phases. The emergent phases include both miscible and immiscible single droplet (SD), multiple droplets (MD), supersolid (SS), and superfluid (SF) states. More intriguing mixed groundstates may occur for an imbalanced binary mixture, including a combination of SS-SF, SS-MD, and SS-SS phases. We observed the dynamical transition from a miscible MD state to an immiscible MD state with multiple domains formed along the axial direction by tuning the inter-species scattering length. Also by linear quenches of intra-species scattering lengths across the aforementioned phases, we monitor the dynamical formation of supersolid clusters and droplet lattices. Although we have demonstrated the results for a Dy-Dy mixture and for a specific parameter range of intra-species and inter-species scattering lengths, our results are generally valid for other dipolar mixtures and may become an important benchmark for future experimental scenarios.