Phase coherence in out-of-equilibrium supersolid states of ultracold dipolar atoms

by P. Ilzhöfer, M. Sohmen, G. Durastante, C. Politi, A. Trautmann, G. Natale, G. Morpurgo, T. Giamarchi, L. Chomaz, M. J. Mark, F. Ferlaino
Abstract:
A supersolid is a counterintuitive phase of matter that combines the global phase coherence of a superfluid with a crystal-like self-modulation in space. Recently, such states have been experimentally realized using dipolar quantum gases. Here we investigate the response of a dipolar supersolid to an interaction quench that shatters the global phase coherence. We identify a parameter regime in which this out-of-equilibrium state rephases, indicating superfluid flow across the sample as well as an efficient dissipation mechanism. We find a crossover to a regime where the tendency to rephase gradually decreases until the system relaxes into an incoherent droplet array. Although a dipolar supersolid is, by its nature, ‘soft’, we capture the essential behaviour of the de- and rephasing process within a rigid Josephson junction array model. Yet, both experiment and simulation indicate that the interaction quench causes substantial collective mode excitations that connect to phonons in solids and affect the phase dynamics.
Reference:
Phase coherence in out-of-equilibrium supersolid states of ultracold dipolar atoms,
P. Ilzhöfer, M. Sohmen, G. Durastante, C. Politi, A. Trautmann, G. Natale, G. Morpurgo, T. Giamarchi, L. Chomaz, M. J. Mark, F. Ferlaino,
Nature Physics, 17, 356-361, 2021.
Bibtex Entry:
@Article{Ilzhoefer2021,

author={P. Ilzhöfer and M. Sohmen and G. Durastante and C. Politi and A. Trautmann and G. Natale and G. Morpurgo and T. Giamarchi and L. Chomaz and M. J. Mark and F. Ferlaino},

title={Phase coherence in out-of-equilibrium supersolid states of ultracold dipolar atoms},

journal={Nature Physics},

year={2021},

month={Jan},

day={04},

volume = {17},

pages = {356-361},

abstract = {A supersolid is a counterintuitive phase of matter that combines the global phase coherence of a superfluid with a crystal-like self-modulation in space. Recently, such states have been experimentally realized using dipolar quantum gases. Here we investigate the response of a dipolar supersolid to an interaction quench that shatters the global phase coherence. We identify a parameter regime in which this out-of-equilibrium state rephases, indicating superfluid flow across the sample as well as an efficient dissipation mechanism. We find a crossover to a regime where the tendency to rephase gradually decreases until the system relaxes into an incoherent droplet array. Although a dipolar supersolid is, by its nature, ‘soft’, we capture the essential behaviour of the de- and rephasing process within a rigid Josephson junction array model. Yet, both experiment and simulation indicate that the interaction quench causes substantial collective mode excitations that connect to phonons in solids and affect the phase dynamics.},

arXiv = {https://arxiv.org/abs/1912.10892},

issn={1745-2481},

doi={10.1038/s41567-020-01100-3},

url={https://doi.org/10.1038/s41567-020-01100-3}

}