Signatures of rigidity and second sound in dipolar supersolids

TL;DR

This paper introduces a dynamical protocol using merging in double-well potentials to detect rigidity, phase coherence, and second sound in dipolar supersolids through simulations.

Contribution

It presents a new method to dynamically probe the superfluid properties and second sound in dipolar supersolids via merging protocols and phase imprinting.

Findings

Supersolids show damped crystal oscillations after barrier removal.

Metastable dark solitons are triggered by phase-imprinted jumps.

Second sound is excited and observed through out-of-phase drift.

Abstract

We propose a dynamical protocol to probe the rigidity and phase coherence of dipolar supersolids by merging initially separated fragments in quasi-one-dimensional (1D) double-well potentials. Simulations based on the extended Gross-Pitaevskii equation reveal distinct dynamical signatures across phases. Supersolids exhibit damped crystal oscillations following barrier removal, with the damping rate reflecting superfluid connectivity. A phase-imprinted jump additionally triggers metastable dark solitons, which excites second sound, as revealed by an out-of-phase drift between the droplet lattice and the superfluid background. Our results show a realizable path to dynamically detect the second sound and rigidity of supersolids, as well as to realize and probe soliton formation.