51. Supersolid behavior of a dipolar Bose-Einstein condensate confined in a tube
- Author
-
Francesco Ancilotto and S. M. Roccuzzo
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Condensed matter physics ,Condensed Matter::Other ,Phonon ,FOS: Physical sciences ,Scattering length ,Roton ,01 natural sciences ,010305 fluids & plasmas ,law.invention ,Superfluidity ,Supersolid ,Quantum Gases (cond-mat.quant-gas) ,law ,0103 physical sciences ,Local-density approximation ,Condensed Matter - Quantum Gases ,010306 general physics ,Bose–Einstein condensate ,Discrete symmetry - Abstract
Motivated by a recent experiment [L.Chomaz et al., Nature Physics 14, 442 (2018)], we perform numerical simulations of a dipolar Bose-Einstein Condensate (BEC) in a tubular confinement at T=0 within Density Functional Theory, where the beyond-mean-field correction to the ground state energy is included in the Local Density Approximation. We study the excitation spectrum of the system by solving the corresponding Bogoliubov-de Gennes equations. The calculated spectrum shows a roton minimum, and the roton gap decreases by reducing the effective scattering length. As the roton gap disappears, the system spontaneously develops in its ground-state a periodic, linear structure formed by denser clusters of atomic dipoles immersed in a dilute superfluid background. This structure shows the hallmarks of a supersolid system, i.e. (i) a finite non-classical translational inertia along the tube axis and (ii) the appearance, besides the phonon mode, of the Nambu-Goldstone gapless mode corresponding to phase fluctuations, and related to the spontaneous breaking of the gauge symmetry. A further decrease in the scattering length eventually leads to the formation of a periodic linear array of self-bound droplets., Comment: 5 pages, 4 figures (version accepted for publication in PRA Rapid Communications)
- Published
- 2019