Phonon Stability of Quantum Droplets in a dipolar Bose gases
Quantum Gases
2022-06-07 v4
Abstract
Stabilized by quantum fluctuations, dipolar Bose-Einstein condensates can form self-bound liquidlike droplets in the mean-field unstable regime. However in the Bogoliubov theory, some phonon energies are imaginary in the long-wavelength limit, implying dynamical instability of this system. A similar instability appears in the Bogoliubov theory of a binary quantum droplet, and is removed due to higher-order quantum fluctuations as shown recently [1]. In this work, we study the phonon energy of a dipolar quantum droplet in the Beliaev formalism, and find that quantum fluctuations can enhance the phonon stability. We obtain the anisotropic sound velocity which can be tested in experiment.
Keywords
Cite
@article{arxiv.2109.03599,
title = {Phonon Stability of Quantum Droplets in a dipolar Bose gases},
author = {Fan Zhang and Lan Yin},
journal= {arXiv preprint arXiv:2109.03599},
year = {2022}
}