Collective Excitations of Self-Bound Droplets of a Dipolar Quantum Fluid

2017/03/31 by D. Baillie, Ryan Wilson, R. M. Wilson +1 · 108 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Dipole #Physics #Quantum #Quantum fluid #Quantum mechanics #Quantum, superfluid, helium dynamics #Quasiparticle #cond-mat.quant-gas

paper · pdf · doi:10.1103/physrevlett.119.255302

published in Physical Review Letters 119(25), 255302 (American Physical Society) · 5 pages, 3 figures

arxiv created 2017/12/22 · openalex publication_date 2017/12/22 · arxiv updated 2017/12/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06

Abstract

We calculate the collective excitations of a dipolar Bose-Einstein condensate in the regime where it self-binds into droplets stabilized by quantum fluctuations. We show that the filament-shaped droplets act as a quasi-one-dimensional waveguide along which low-angular-momentum phonons propagate. The evaporation (unbinding) threshold occurring as the atom number N is reduced to the critical value N_c is associated with a monopolelike excitation going soft as ε₀∼(N-N_c)^1/4. Considering the system in the presence of a trapping potential, we quantify the crossover from a trap-bound condensate to a self-bound droplet.

Citations

• Instabilities and the roton spectrum of a quasi-1D Bose-Einstein condensed gas with dipole-dipole interactions
• Helium nanodroplets and trapped Bose–Einstein condensates as prototypes of finite quantum fluids
• Spectroscopy and dynamics in helium nanodroplets
• Roton-Maxon Spectrum and Stability of Trapped Dipolar Bose-Einstein Condensates
• Mean-field expansion in Bose-Einstein condensates with finite-range interactions
• Beyond mean-field low-lying excitations of dipolar Bose gases

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